Question

решиье за 40, 2 задания​

Answer 1

$4)quad 7x-3y=3quad (-3;y)\\7cdot(-3)-3y=3\\-21-3y=3\\-3y=3+21\\-3y=24\\3y=-24\\boxed{y=-8}\\\5)quad5x-3y=aquad(-1;3)\\5cdot(-1)-3cdot3=a\\a=-5-9\\boxed{a=-14}$