Let f(g(x)) = 3x + 3 and f(x) = x + 6. If g(x) = ax + b, compute a + b.
start with this
f(x) = x + 6. and g(x) = ax + b
f(g(x)) = g(x)+6
so
f(g(x)) = ax+b+6
which means
3x+3=ax+(b+6)
now just equate coefficients. :)
