Which values of x and y would make the following expression represent a real number? (4+5i)(x+ yi)
Ox=4,y= 5
Ox=-4, y = 0
Ox=4, y=-5
Ox=0, y= 5
Answers
Answer:
C
Step-by-step explanation:
We have the expression [tex](4+5i)(x+yi)[/tex] and we want to find the values of [tex]x[/tex] and [tex]y[/tex] such that the expression will evaluate to a real number.
So, let's first expand the expression. Distribute:
[tex]=4(x+yi)+5i(x+yi)[/tex]
Distribute:
[tex]=4x+4yi+5xi+5yi^2[/tex]
Simplify:
[tex]=(4x-5y)+(4yi+5xi)[/tex]
So, we want to make the second part within the real numbers.
Notice that we only have two ways of doing this: 1) Either both [tex]x[/tex] and [tex]y[/tex] are imaginary numbers themselves canceling out the [tex]i[/tex], or 2), the entire expression equals 0.
Since our answer choices consists of only real numbers, this means that the imaginary part must be equal to 0. So:
[tex]4yi+5xi=0[/tex]
We can divide everything by [tex]i[/tex]:
[tex]4y+5x=0[/tex]
Now, we can use our answer choices.
Running down the list, we can see that the choice that works is C. If we substitute the values of C into the equation, we get:
[tex]4(-5)+5(4)=0\\\Rightarrow -20+20=0\stackrel{\checkmark}{=}0[/tex]
Therefore, our answer is C.
Answer:
c
Step-by-step explanation:
Related Questions
Mandy makes cupcakes, she uses 8 3/4 cups of flour for 12 cupcakes. How many cups of flour are needed to make 1 cupcake? Explain how you found each amount.
Answers
Answer:
Step-by-step explanation:
.75=3/4
8.75 cups divided by 12 cupcakes = .73 (rounded up) cups of flour per cupcake
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Answer:33
Step-by-step explanation: You do what's inside the parenthesis first then you divide the number by 6 and lastly you add 5squared which is 25 to the quotient.
Is Mr. Martin a hero? xplain why or why not.
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Answer:
mr martin was a hero in my eyes he saved many lives and was one of the strongest people to ever live (who is mr martin?)
Step-by-step explanation:
please help! i would appreciate it!
Answers
Answer:
(Answer
Step-by-step explanation:
deleted)
Please help I’m not sure what it is don’t make fun I’m not good at math
Answers
Answer:
3.75 or 3[tex]\frac{3}{4}[/tex]
Step-by-step explanation:
The first thing we can find is the scale factor of the two triangles. You can see that the corresponding sides AB and A'B' are 2 and 8 respectively, and since the two triangles are similar, you can say that triangle ABC is shrunk by a factor of 2/8 or 1/4.
Next, we need to figure out what side B'C' is and we can do this using the Pythagorean theorem [tex]a^{2}[/tex]+[tex]b^{2}[/tex] = [tex]c^{2}[/tex]. Using this, we know that [tex]8^{2}[/tex]+
Now, since ABC is shrunk by 1/4 and the corresponding side of BC is equal to 15, we need to multiply 15 by 1/4 and you would find that BC is 3.75 or 3[tex]\frac{3}{4}[/tex].
If a system of linear equations has the unique solution (2, -3), then its graph consists of what?
•parallel lines
•lines that intersect at a single point
•identical lines
•a y-intercept at -3
Answers
Answer: B - lines that intersect at a single point
Step-by-step explanation: Just took a test
Hmmmmmmmmmmmmmmm?????????
Answers
Answer:whats the question?????
Step-by-step explanation:
Ignore a and b but can you help with c and d? Plz I’ll mark you as a brainiest
Answers
140+2x=180
2x=40
x=20
C: 2x+20=60
2x=40
x=20
D: 3x+10=100
3x=90
x=30
simplify the following
Answers
Answer:
D. 64 z^ 2
Step-by-step explanation:
Simplify the expression.
evaluate = (√5+2√6) + (√8-√2√15)
Answers
Answer: 2√2 + 3√8 = 2√2 + 6√2 = 8√2 , because we simplified √8 = √(4 * 2)
Answer:
[tex]\sqrt{5}+2\sqrt{6} + 2\sqrt{2} - \sqrt{30} \approx 4.5[/tex]
Step-by-step explanation:
[tex](\sqrt{5}+2\sqrt{6} ) + (\sqrt{8} - \sqrt{2} \cdot \sqrt{15} )[/tex]
[tex](\sqrt{5}+2\sqrt{6} ) + (\sqrt{8} - \sqrt{30} )[/tex]
[tex](\sqrt{5}+2\sqrt{6} ) + (2\sqrt{2} - \sqrt{30} )[/tex]
[tex]\sqrt{5}+2\sqrt{6} + 2\sqrt{2} - \sqrt{30} \approx 4.5[/tex]
Which table represents a linear function?
answers are in the picture plz help im timed
Answers
Answer: first table
Step-by-step explanation: go with the first one
Which pair of quantities form a proportional relationship? Select all that apply
Answers
Answer:
The 4th and 6th
Step-by-step explanation:
√12
A. 2√5
B. 2√3
Which one?
Answers
Answer:
B. [tex]2\sqrt{3}[/tex]
Hope this helps!
Answer:
B.2√3
Explanation:
√2^2×√3
√2^2√3
2√3
8. PLS ANSWER!!!!
and show work
Answers
Answer:
The equation of the parallel line is y = 5x + 11
Step-by-step explanation:
→ Parallel lines have same slopes and different y-intercepts
→ The slope-intercept form of the linear equation is y = m x + b, where
m is the slopeb is the y-interceptIn our question
∵ The equation of the given line is y = 5x + 2
→ Compare it with the form above to find its slope
∴ m = 5
∵ The two lines are parallel
∴ Their slopes are equal
∴ The slope of the parallel line is 5
→ Substitute it in the form of the equation above
∴ y = 5x + b
→ To find the value of b substitute x and y in the equation by the
coordinates of any point on the line
∵ The line passes through point (-2, 1)
∴ x = -2 and y = 1
∵ 1 = 5(-2) + b
∴ 1 = -10 + b
→ Add 10 to both sides
∴ 1 + 10 = -10 + 10 + b
∴ 11 = b
→ Substitute value of b in the equation
∴ y = 5x + 11
∴ The equation of the parallel line is y = 5x + 11
How many lines of symmetry, does this quadrilateral have
Answers
Answer:
im going to say 4 hope it helps
Step-by-step explanation:
I need help with 9and 10 pleas
Answers
10 is either a or b
What is the solution of 8 + a = 13? Justify each step. A. The steps are: (1) 8 + a = 13 (2) 8 + 8 + a = 13 + 8 (3) a = 21 The reasons are: (1) original equation (2) Addition Property of Equality (3) Simplify. B. The steps are: (1) 8 + a = 13 (2) 8 − 8 + a = 13 (3) a = 13 The reasons are: (1) original equation (2) Subtraction Property of Equality (3) Simplify. C. The steps are: (1) 8 + a = 13 (2) 8 − 8 + a = 13 − 8 (3) a = 5 The reasons are: (1) original equation (2) Subtraction Property of Equality (3) Simplify. D. The steps are: (1) 8 + a = 13 (2) 88+a=138 (3) a = 1.63 The reasons are: (1) original equation (2) Division Property of Equality (3) Simplify.
Answers
Answer:
C. The steps are: (1) 8 + a = 13 (2) 8 − 8 + a = 13 − 8 (3) a = 5 The reasons are: (1) original equation (2) Subtraction Property of Equality (3) Simplify.
Step-by-step explanation:
8 + a = 13 (original Equation)
Subtract 8 from both sides
8 + a - 8 = 13 - 8 ( subtraction property of equality
a = 5 (Simplify)
The correct answer is option C
C. The steps are: (1) 8 + a = 13 (2) 8 − 8 + a = 13 − 8 (3) a = 5 The reasons are: (1) original equation (2) Subtraction Property of Equality (3) Simplify.
Classify the system of equations.
2x = 5 - y
-3+y = -2x + 3
Click on the correct answer.
coincident
intersecting
parallel
Answers
Answer:
Parallel
Step-by-step explanation:
Solve the inequality below.
4(x + 3) < 6x – 2
Answers
Answer:
X > 7
Step-by-step explanation:
4(x + 3) < 6x – 2
4x + 12 < 6x -2
-6x -6x
-2x + 12 < -2
-12 -12
-2x < -14
----- -----
-2 -2
x > 7
The < change because it was divided by a negative number
Write an equation in slope-intercept form of the line that passes through the given point and is perpendicular to the graph of the given equation.
(-5,8); y=1/5x-3
Answers
Answer:
y = –5x – 17
Step-by-step explanation:
First, we shall determine the slope of the equation y = 1/5x – 3.
The slope of the equation y = 1/5x – 3 can be obtained by comparing the equation with y = mx + c.
This is illustrated below:
y = 1/5x – 3
y = mx + c
Thus, the slope (m) of equation
y = 1/5x – 3 is 1/5
Next, we shall determine the slope of the line perpendicular to the equation as follow:
For perpendicular lines, their slope (m1 and m2) are related as follow:
m1 × m2 = –1
m1 = 1/5
1/5 × m2 = –1
m2/5 = –1
Cross multiply
m2 = 5 × –1
m2 = –5
Therefore, the slope of the line is –5.
Finally, we shall determine the equation of the line as follow:
Coordinate = (–5, 8)
x1 coordinate = –5
y1 coordinate = 8
Slope (m) = –5
y – y1 = m(x –x1)
y – 8 = –5(x – (–5))
y – 8 = –5(x + 5)
y – 8 = –5x – 25
Rearrange
y = –5x – 25 + 8
y = –5x – 17
Therefore, the equation is y = –5x – 17.
Simplify this equation (3√2)²
Answers
Answer:
18
Step-by-step explanation:
A car travels 43 km in 56 minutes.
What is its average speed in km/h?
Give your answer rounded to 1 decimal place.
Answers
Answer:
[tex]\displaystyle v=46.07\ Km/h[/tex]
Step-by-step explanation:
Speed
The speed is the ratio between the distance x traveled by an object and the time t taken.
[tex]\displaystyle v=\frac{x}{t}[/tex]
The car travels x=43 Km in t=56 minutes. We are required to express the speed in Km/h. The time needs to be expressed in hours:
[tex]t = 56 / 60 = 0.933\ h[/tex]
Now apply the formula:
[tex]\boxed{\displaystyle v=\frac{43}{0.933}=46.07\ Km/h}[/tex]
when you apply combine like terms to the right side of the equation what do you end up with?
Answers
Since the first term and the last term, 6x and -5x are like terms you add them. 6 plus -5 is one. In this case it would be x.(it is not necessary to put 1 in front of the x). And 7 is positive and it is the only term left by itself.
Select each set of points that are colinear.
Answers
Answer:
friend, a points are collinear
Answer:
points K and R are colinear
Step-by-step explanation:
What is the length of c on the graph below?
6
10
8
14
Answers
Answer:
10 is the answer to the question
1.What is the standard form of a linear equation?
A.x+y=0
B.y= MX+b
C. m=rise/run
D. ax +By=C
2.Which term could be used to describe the graph of a line on a coordinate plane?
A. independent variable
B. test points
C. set of all solutions
D. dependent variable
3.Explain whether the points (−13,4), (−7,3), (−1,2), (5,1), (11,0), (17,−1) represent the set of all the solutions for the equation y=−1/6x+11/6.
A.Yes, because all the solutions of y=−1/6x+11/6 need to be integer values for x and y.
B.No, because the point (17,−1) is not on the line that represents the equation y=−1/6x+11/6.
C.No, because the set of all solutions of y=−1/6x+11/6 is represented by the line of the equation.
D. Yes, because all of the points that are listed are on the line y=−1/6x+11/6.
Answer them all in one answer please and thank you.
Answers
Answer:
1. D
sorry I know only first one
Please answerrr!!! (don’t answer if you don’t know it) will give brainliest
Answers
Solve the following equation
5(3x+5)=3(5x+1)
Answers
Answer:
No solutions
Step-by-step explanation:
Let's solve your equation step-by-step.
5(3x+5)=3(5x+1)
Step 1: Simplify both sides of the equation.
5(3x+5)=3(5x+1)
(5)(3x)+(5)(5)=(3)(5x)+(3)(1)(Distribute)
15x+25=15x+3
Step 2: Subtract 15x from both sides.
15x+25−15x=15x+3−15x
25=3
Step 3: Subtract 25 from both sides.
25−25=3−25
0=−22
Answer:
There are no solutions.
Write the equation in vertex form using the following information: vertex (4, -6) and a=1.
Submit
Answers
Answer:
y = (x - 4)² - 6Step-by-step explanation:
An equation of a quadratic function in a vertex form is y=a(x-h)²+k, where vertex is (h, k)
vertex (4, -6) means h = 4 and k = - 6
So:
y = 1(x - 4)² + (-6)
y = (x - 4)² - 6
A number n minus 3 is at least –5.
Answers
Answer:
n-3≥-5
If you need the equation solved...
n-3≥-5
+3 +3
n≥-2
Hope this helped!! Have a great day c: