Решите y=-21x-15 и y=21x+69

Question

Решите
y=-21x-15 и y=21x+69

Answer 1

(y=-21x-15
(y=21x+69
y=-21x-15
-21x-15=21x+69
-21x-15-21x-69=0
-42x-84=0
-42x=84
x=-2
y=-21*(-2)-15
y=27