Question

2x-y=3
5x+y=1

resultado

Answer 1

$2x - y = 3 \\ 5x + y = 1 \\ \\ 2x + 5x - y + y = 3 + 1 \\ 7x = 4 \\ x = \frac{4}{7 } \\ \\ 2( \frac{4}{7} ) - y = 3 \\ \frac{8}{7} - y = 3 \\ \frac{8}{7} - \frac{7y}{7} = \frac{21}{7} \\ 8 - 7y = 21 \\ - 7y = 21 - 8 \\ - 7y = 13 \: \: \: \: ( \times - 1) \\ 7y = - 13 \\ y = \frac{ - 13}{7}$

Resposta final: x = 4/7 ; y = -13/7