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

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