Question

select the correct answer. what are the solutions of this quadratic equation? x² − 10x = -34 a. x=-8,-2 b. x=5±3i c. x=-5±3i d. x=-5±59

Answer 1

b

Explanation:

given

x² - 10x = - 34

using the method of completing the square to solve for x

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

x² + 2(- 5)x + 25 = - 34 + 25

(x - 5)² = - 9 ( take square root of both sides )

`√((x-5)^2)` = ±
`√(-9)`

x - 5 = ±
`√(9(-1))` = ± (
`√(9)` ×
`√(-1)` ) = ± 3i [
`√(-1)` = i ]

add 5 to both sides

x = 5 ± 3i