Question

If f(x)=5x^2+8x and g(x)=-2x^2+7 find (f+g)(x)

Answer 1

`\displaystyle{(f+g)(x)=3x^2+8x+7}`

Explanation:

Given both functions f(x) and g(x):

`\displaystyle{f(x)=5x^2+8x}\\\\\displaystyle{g(x)=-2x^2+7}`

Finding (f+g)(x), is the same as finding the sum of both functions, f(x) + g(x). Therefore:

`\displaystyle{(f+g)(x) = f(x)+g(x)}\\\\\displaystyle{(f+g)(x)=(5x^2+8x)+(-2x^2+7)}\\\\\displaystyle{(f+g)(x)=5x^2+8x-2x^2+7}\\\\\displaystyle{(f+g)(x)=3x^2+8x+7}`