Question

If f(x)=2x−2 and g(x)=x2−8x+19, then f(x)=g(x) for what values of x?

x=−1 and x=−4


x=−3 and x=−7


x=1 and x=4


x=3 and x=7

Answer 1

d: x=3 and x=7

Explanation:

Answer 2

D) x =3 and x =7

Explanation:

Step(i):-

Given function f(x) = 2x -2

g(x) = x² - 8x +19

Given that f(x) = g(x)

⇒ 2x -2 = x² - 8x +19

⇒ x² - 8x +19 -2x +2 =0

⇒ x² -10x +21 =0

Step(ii):-

The factors are x² -10x +21 =0

⇒ x² - 7x - 3x +21 =0

⇒ x( x-7) -3( x-7) =0

⇒ (x-3)(x-7) =0

x =3 and x =7