SOLUTION: help pls f(x) = 2x + 7 and g(x) = 3x + c. Find c if (f \circ g)(x) = (g \circ f)(x) for all x.

Algebra ->  Equations -> SOLUTION: help pls f(x) = 2x + 7 and g(x) = 3x + c. Find c if (f \circ g)(x) = (g \circ f)(x) for all x.      Log On


   

Question 863151: help pls f(x) = 2x + 7 and g(x) = 3x + c. Find c if (f \circ g)(x) = (g \circ f)(x) for all x.
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
You appear to be trying to say this:
f(x) = 2x + 7 and g(x) = 3x + c. Find c if %28f%28g%29%29%28x%29+=+%28g%28f%29%29%28x%29 for all x.

f o g
2%283x%2Bc%29%2B7
6x%2B2c%2B7

g o f
3%282x%2B7%29%2Bc
6x%2B18%2Bc

f%28g%28x%29%29=g%28f%28x%29%29
6x%2B2c%2B7=6x%2B18%2Bc
2c%2B7=18%2Bc
2c-c%2B7=18%2Bc-c
c%2B7=18
c=18-7
highlight%28c=11%29