Diketahui f(x)=2x-1 DAN (G°f) (x)=4xkuadrat -10x+5. Nilai G(-1)=

y=2x-1
x=y-1/2
4x^2-10x+5=g(x)
4(y-1/2)^2-10(y-1/2)+5=g(x)
y^2-2y+1-5y+5+5=g(x)
y^2-7y+10=g(x)
g(x)=x^2-7x+10
g(-1)=-1^2-7(-1)+10
g(-1)=1+7+10
g(-1)=18