fx=3x-1 , g(x)=2x²+3 , (g°f)(1)=.......?

(gof)(1)
2(3(1)-1)^2+3
2(4) + 3
11

(g o f) (x) =g(f(x))
=g(3x-1)
=2(3x-1)²+3
=2(9x²-6x+1)+3
=18x²-12x+2+3
=18x²-12x+5
(g o f) (1)=18x²-12x+5
=18(1)²-12(1)+5
=18-12+4=11