Question

.

Answer 1

first find the f(3)
what wil u get ?

Answer 2

can u find f(3)... ? or may i help u ?

Answer 3

f(3) means the value you get if u plug 3 instead of x in f(x)
i.e. f(x) = 2x+1
f(3) = 2(3) + 1
= (2x3) +1
= 7

got it ?

Answer 4

and g[f(3)] means
what u get if u plug f(3) instead of x in g(x)
i.e
g(x)=(3x-1)/2
= { 3[f(3)] - 1 } / 2
but we know f(3) = 7
so..
= (3(7) - 1) /2
= [ (3x7) - 1] /2
= (21 - 1)/2
= 10

GOT IT :) ?