Question 852047
IF {{{f(x)=2x^3}}} and {{{g(x)=1/4^x=(1/4)^x}}}
{{{g(7x+7)=1/4^(7x+7)}}} .
So far, it was just a question of substituting.
Maybe that expression can be simplified (now or later).
Then (simplifying later rather than sooner)
{{{f(g(7x+7))=f(1/4^(7x+7))=2*(1/4^(7x+7))^3=2/4^(3*(7x+7))=2/4^(21x+21)=2/(2^2)^(21x+21)=2/2^(2*(21x+21))=2/2^(42x+42)=1/2^(42x+41)}}}