Question

Find the value’s of x given that f(x) = x^2 - 2x - 3 and f(x) = 5

Answer 1

4 and - 2

Explanation:

f ( x ) = x^2 - 2x - 3

f ( x ) = 5

x^2 - 2x - 3 = 5

x^2 - 2x - 3 - 5 = 0

x^2 - 2x - 8 = 0

x^2 + 2x - 4x - 8 = 0

x ( x + 2 ) - 4 ( x + 2 ) = 0

( x - 4 ) ( x + 2 ) = 0

x - 4 = 0

x = 4

x + 2 = 0

x = - 2

x has 2 values,

x = 4, - 2