Question

Select the correct answer.

What are the the values of x and y that satisfy this equation?
(x + yi) + (4+9i) = 9-4i

Answer 1

Answer: Option A; x = 5, y = -13

Explanation:

We have the equation:

(x + yi) + (4+9i) = 9-4i

Solving the left side we have:

x + y*i + 4 + 9*i = 9 - 4*i

(x + 4) + (y + 9)*i = 9 - 4*i

The real part is x + 4, and this must be equal to the real part in the right that is 9, then:

x + 4 = 9

x = 9 - 4 = 5

x = 5

And the imaginary part in the left needs to be equal to the imaginary part in the right, then:

y + 9 = -4

y = -4 - 9 = -13

y = -13

then the solution is x = 5, y = -13

The correct option is A