USE MATLAB PLEASE

$11\mathrm{.}15$ Use the Gauss$-$Seidel method $($a$)$ without relaxation and $($b$)$ with relaxation $)=(1\mathrm{.}2$ to solve the following system to a tolerance of ${}_s=5\%.$ If necessary, rearrange the equations to achieve convergence.

$2x_1-6x_2-x_3=-38$

$-3x_1-x_2+7x_3=-34$

$-8x_1+x_2-2x_3=-20$