[tex]\bf \begin{cases} f(x) = x-1\\ g(x) = 3x^2+7x-4 \end{cases} \\\\[-0.35em] ~\dotfill\\\\ g(~~f(x)~~)=3[f(x)]^2+7[f(x)]-4 \\\\\\ g(~~f(x)~~)=3[x-1]^2+7[x-1]-4 \\\\\\ g(~~f(x)~~)=3[x-1][x-1]+7[x-1]-4 \\\\\\ g(~~f(x)~~)=3[\stackrel{FOIL}{x^2-2x+1}]+7x-7-4 \\\\\\ g(~~f(x)~~)=[3x^2-6x+3]+7x-11 \\\\\\ g(~~f(x)~~)=3x^2+x-8[/tex]
