Question

1)

{-5x+y-10=0
{2x-2y+6=0

2)

{3x+5y-2=0
{x-y-4=0​

Answer 1

$- 5x + y - 10 = 0$

$y = 10 + 5x$

$2x - 2y + 6 = 0$

$- 2y = - 6 - 2x$

$y = x + 3$

$10 + 5x = x + 3$

$5x - x = 3 - 10$

$4x = - 7$

$x = - \frac{7}{4}$

$5 \times ( \frac{ - 7}{4} ) + 10 = - \frac{7}{4} + 3$

$- \frac{35}{4} + \frac{40}{4} = - \frac{7}{4} + \frac{12}{4}$

$\frac{5}{4} = \frac{5}{4} = y$