First to make it easier you can convert ( g o f)(x) to g (f(x)) so that it is more clear.All you need to do is input function f into the function g in the place of "x - the unknown ".Therefore, since function f(x) is 6x+4, and in function g(x) the unknown is multiplied by 3 and squared,the function( g o f)(x) is equal to 3(6x+4)^2+7to calculate ( g o f)(x) for x=2 we need to substitute 2 for x( g o f)(2)=3(62+4)^2+7first you square the result from the brackets - (62+4)^2=16^2=256now you multiply the squared result by 3 and add 7 - 256*3+7=775Thus ( g o f)(x) for x=2 is 775.