Question

Which of the following is a solution of x2 − 10x = −36? (6 points)

Select one:
a. negative 5 minus i square root of 10
b. 5 plus i square root of 61
c. negative 5 minus i square root of 11
d. 5 plus i square root of 11

Answer 1

Answer:

D

Step-by-step explanation:

Given

x² - 10x = - 36

Solve using the method of completing the square

add ( half the coefficient of the x- term )² to both sides

x² + 2(- 5)x + 25 = - 36 + 25

(x - 5)² = - 11 ( take the square root of both sides )

x - 5 = ± $\sqrt{-11}$ ( add 5 to both sides )

x = 5 ± i$\sqrt{11}$

Thus

x = 5 - i$\sqrt11}$ or x = 5 + i$\sqrt{11}$