$\begin{aligned}g(x)&=x^3+2\\\\ g(3)&=({3})^3 +2~~~~~~~~~~~~~~~~~~~\small{\gray{\text{Sustituye }x={3.}}}\\\\ &={29}\end{aligned}$

$\begin{aligned}f(x)&=3x-1\\\\ f( {{29}})&=3({29}) - 1~~~~~~~~~~~~~~~\small{\gray{\text{Sustituye }x= {29.}}}\\\\ &={86}\\\\ \end{aligned}$

$\begin{aligned}f(\blueE x)&=3\blueE x-1\\\\ f(\maroonD{g(x)}) &= 3(\maroonD{g(x)})-1 \\ \end{aligned}$

$\begin{aligned}{f(g(x))}&=3(g(x))-1 \\\\ &=3({x^3+2})-1 \\\\ &=3x^3+6-1\\\\ &=3x^3+5 \end{aligned}$

$\begin{aligned} f( g(x))&= 3x^3+5\\ \\ f( g( 3))&= 3( 3)^3+5 \\\\ &= {86} \end{aligned}$

$(f\circ g)(x)=f(g(x))$left parenthesis, f, circle, g, right parenthesis, left parenthesis, x, right parenthesis, equals, f, left parenthesis, g, left parenthesis, x, right parenthesis, right parenthesis

$\begin{aligned}(h\circ g)(x)&=h(g(x))&\small{\gray{\text{Define.}}}\\\\ &=(g(x))^2-2(g(x))&\small{\gray{\text{Sustituye } g(x) \text{ por } x\text{ en la función }h.}}\\\\ &=({x+4})^2 -2({x+4})&\small{\gray{\text{Sustituye } x+4 \text{ en lugar de } g(x).}}\\\\ &=x^2+8x+16-2x-8&\small{\gray{\text{Distribuye.}}}\\\\ &=x^2+6x+8&\small{\gray{\text{Combina términos semejantes.}}}\end{aligned}$

$\begin{aligned}(h\circ g)(x)&=x^2+6x+8\\\\ (h\circ g)(-2)&=(-2)^2+6(-2)+8\\\\ &=4-12+8\\\\ &=0\\\\ \end{aligned}$

$\begin{aligned}(h\circ g)(-2)&=h(g(-2))\\\\ &=h(2)~~~~~~~~\small{\gray{\text{Pues }g(-2)=-2+4=2}}\\\\ &=0~~~~~~~~~~~~~\small{\gray{\text{Pues }h(2)=2^2-2(2)=0}}\\\\ \end{aligned}$