Answer:
(gof)(5)=1246
Explanation:
first lets find for (gof)
(gof)=g(f(x))
=x(3x+1)^2-2(3x+1)-6
=x(9x^2+6x+1)-6x+2-6
=9x^3+6x^2+x-6x-4
=9x^3+6x^2-5x-4
now let's find for (gof)(5)
we know(gof)=9x3+6x2-5x-4
so (gof)(5)=9(5)^3+6(5)^2-5(5)-4
=9(125)+6(25)-25-4
=1125+150-29
(gof)(5)=1246