Question

Let f(x)=7x^3 −2x−12 and g(x)=−3x^3 -8x^2 +10x . please help

What is the function rule for (f+g)(x) ?


a.(f+g)(x)=4x^6 −8x^2 +8x−12

b.(f+g)(x)=4x^3 −12x^2 +8x−12

c.(f+g)(x)=4x^3−8x^2+8x−12

d.(f+g)(x)=4x^6−8x^2+12x−12

Answer 1

(f+g)(x) = f(x) +g(x)
= (7x^3 −2x−12) +(−3x^3 -8x^2 +10x)
= x^3(7 -3) +x^2(-8) +x(-2+10) +(-12)
= 4x^3 -8x^2 +8x -12

Corresponds to selection C.