Question

If
f(x)=5x^3+3x^2-7x
g(x)=3x^3-5x^2-2
h(x)=-9x^2+8

Find g(x)-f(x)

Answer 1

\[f(x) = 5x^3 +3x^2-7x\]\[g(x)=3x^3-5x^2 -2\]\[g(x)-f(x) = 5x^3 +3x^2 -7x - (3x^3 -5x^2-2)=\]\[(5-3)x^3 +(3+5)x^2-7x+2=2x^3+8x^2-7x+2\]

Answer 2

Since it is g(x)-f(x), would it be -2x^3-2x^2-7x-2?

Answer 3

Did I do the math wrong above?

Answer 4

I think we both did. We should have multiplied negative 1 to f(x) and we should have gotten -2x^3-8x^2+7x-2. Thanks for helping me work it through!

Answer 5

Isn't that what I did?\[g(x)-f(x) = 5x^3 +3x^2 -7x - (3x^3 -5x^2-2)=\]

Answer 6

\[g(x)-f(x) = (5x^3 +3x^2 -7x) - (3x^3 -5x^2-2)=\]

Answer 7

\[(5-3)x^3 +(3+5)x^2-7x+2=2x^3+8x^2-7x+2\]