Question

b {x=3y
{x-2y=3

c {2x+y=-3
{x+y= -1 URGENTE PRECISO DOS CALCULOS

Answer 1

$\large\boxed{\begin{array}{l}\rm b)\\\begin{cases}\sf x=3y\\\sf x-2y=3\end{cases}\\\sf 3y-2y=3\\\sf y=3\\\sf x=3y\\\sf x=3\cdot3\\\sf x=9\\\sf S=\{9,3\}\end{array}}$

$\large\boxed{\begin{array}{l}\rm c)\\\begin{cases}\sf2x+y= -3\\\sf x+y=-1\end{cases}\\\\+\underline{\begin{cases}\sf 2x+\diagdown\!\!\!y=-3\\\sf-x-\diagdown\!\!\!y=1\end{cases}}\\\sf x=-2\\\sf x+y=-1\\\sf y=-x-1\\\sf y=-(-2)-1\\\sf y=2-1\\\sf y=1\\\sf S=\{-2,1\}\end{array}}$