Question

1) If - x + y = - 4 , - x + 2 y = 4 then (x ,y) = …….. *​

Answer 1

$- x + y = - 4$

$- x + 2y = 4$

$change \: sign \: of \: first \: equation$

$x - y = 4$

$- x + 2y = 4$

$add \: both$

$y = 8$

$x - y = 4$

$put \: y = 8$

$x - 8 = 4$

$x = 4 + 8$

$x = 12$

(x, y) = (12, 8)