Question

{x-y=2
{4x+y=32

{x+y=18
{4x-y=12
​

Answer 1

Primeiro sistema:

$\displaystyle\left\{ \begin{array}{l} x-y=2\\ 4x+y=32 \end{array}\right.\\\\x+4x-y+y=2+32\\5x=34\\\\x=\frac{34}{5}\\\\\\x-y=2\\\frac{34}{5}-y=2\\\\-y=2-\frac{34}{5}\\\\-y=-\frac{24}{5}\\\\y=\frac{24}{5}$

Segundo sistema:

$\displaystyle\left\{ \begin{array}{l} x+y=18\\ 4x-y=12 \end{array}\right\\\\x+4x+y-y=18+12\\5x=30\\x=6\\\\x+y=18\\6+y=18\\y=18-6\\y=12$