SOLUTION: Let f(x)=x^2-4 and g(x)=-5X+3 f(x)= -3x^2+ -4, g(x)=x3+3X^2

Algebra ->  Functions -> SOLUTION: Let f(x)=x^2-4 and g(x)=-5X+3 f(x)= -3x^2+ -4, g(x)=x3+3X^2      Log On


   

Question 508898: Let f(x)=x^2-4 and g(x)=-5X+3
f(x)= -3x^2+ -4, g(x)=x3+3X^2
Answer by oberobic(2304) About Me  (Show Source):
You can put this solution on YOUR website!
OK. But what do you want to do with them?
(f + g)x?
(f - g)x?
(f * g)x?
(f / g)x?
(f o g)x?
.
f(x) = x^2 -4
f(x) = (x-2)(x+2)
.
g(x) = 5x + 3
.
You can graph them. f(x) is red; g(x) is green.
.
graph%28500%2C500%2C-50%2C50%2C-50%2C50%2Cx%5E2-4%2C5%2Ax%2B3%29
.
OR you can set them = to each other.
.
f(x) = g(x)
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x^2-4 = 5x + 3
subtract 5x from both sides
x^2 -5x -4 = 3
subtract 3 from both sides
x^2 -5x -7 = 0
Which can only be solved using the quadratic equation.
But you can graph it.
.
graph%28500%2C500%2C-20%2C20%2C-20%2C20%2Cx%5E2-5%2Ax-7%29
.
OR you can add them.
.
f(x) + g(x) = (f+g)x
.
f(x) = x^2 -4
g(x) = 5x + 3
.
(f+g)x = x^2 +5x -7
.
So, you need to re-read the question to see what they're asking you do with f(x) and g(x).