Question

I have been asked this question and I substituted the value of x in f with g(x), and rearranged the equality but is incorrect. ​

Answer 1

p = 2 and q = 14

Explanation:

f(g(x)) = 3(px + 4) + p

f(g(x)) = 3px + 12 + p

6x + q = 3px + 12 + p

The trick here is to equate the coefficients.

6 = 3p and q = 12 + p

p = 2 and q = 14

Answer 2

if fg(x)=6x+q

then f(gx) =6x+q

3(px+4)+p =6x+q

3px+12+p = 6x+q

3px+p = 6x+q-12

make p the subject

p( 3x+1) = 6x+q-12

p= (6x + q -12 )/ 3x +1