SOLUTION: Did I answer these correctly? 4)f(x) = 2x + 3 g(x)= 2x^2 + 2x Find f(g(x) ) 2(2x^2+2x)+3 =4x(x+1)+3 = 4x^2+4x+3 5. f(x) = 5x + 3 g(x) = 2x^2-2x + 2 Find (fg(x) ) (5x+

Algebra ->  Rational-functions -> SOLUTION: Did I answer these correctly? 4)f(x) = 2x + 3 g(x)= 2x^2 + 2x Find f(g(x) ) 2(2x^2+2x)+3 =4x(x+1)+3 = 4x^2+4x+3 5. f(x) = 5x + 3 g(x) = 2x^2-2x + 2 Find (fg(x) ) (5x+      Log On


   



Question 1002750: Did I answer these correctly?
4)f(x) = 2x + 3
g(x)= 2x^2 + 2x
Find f(g(x) )
2(2x^2+2x)+3
=4x(x+1)+3
= 4x^2+4x+3
5. f(x) = 5x + 3
g(x) = 2x^2-2x + 2
Find (fg(x) )
(5x+3)(2x^2-2x+2)
2(5x+3)(x^2-x+1)
10x^3-4x^2+4x+6
6)f(x)=3x
g(x)= -2x^2 -2x
Find (f - g)(x)
3x-(-2x^2-2x)
=3x+2x^2+2x
=2x^2+5x

7)f(x)=3x + 1
g(x)=x^2-5x -2
Find g(f(x) )
(3x+1)^2-5(3x+1)-2
=6x+1+9x^2-15x-5-2
=9x^2-9x-6

Answer by ikleyn(52788) About Me  (Show Source):
You can put this solution on YOUR website!
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Did I answer these correctly?

4) f(x) = 2x + 3
   g(x)= 2x^2 + 2x 
   Find f(g(x) )
   2(2x^2+2x)+3
   =4x(x+1)+3
   = 4x^2+4x+3       <<<--- correct.

5) f(x) = 5x + 3
   g(x) = 2x^2-2x + 2 
   Find (fg(x) )
   (5x+3)(2x^2-2x+2)
   2(5x+3)(x^2-x+1)
   10x^3-4x^2+4x+6   <<<--- correct.

6) f(x)=3x
   g(x)= -2x^2 -2x
   Find (f - g)(x)
   3x-(-2x^2-2x)
   =3x+2x^2+2x
   =2x^2+5x          <<<--- correct.

7) f(x)=3x + 1
   g(x)=x^2-5x -2
   Find g(f(x) )
   (3x+1)^2-5(3x+1)-2
   =6x+1+9x^2-15x-5-2
   =9x^2-9x-6        <<<--- correct.