Question

If f(x) = x2 – 2x and g(x) = 6x + 4, for which value of x does (f + g)(x) = 0? Х оооо

Answer 1

Answer:

(f+g) (x) =0 for x=-2

Step-by-step explanation:

f(x) = x^2 – 2x, g(x) = 6x + 4,

(f+g) (x) =f(x) +g(x) =

(x^2 – 2x) + (6x + 4) =

x^2 – 2x+ 6x + 4=

x^2 +4x+4

(f+g)(x) =x^2 +4x+4=0 (quvadratic equation)

x^2 +4x+4=x^2 +2x*2+2^2=(x+2)^2

then

(x+2)^2 =0

x+2=0

x=-2

(f+g) (x) =0 for x=-2