Question

решите систему уравнений:
4x-3y=-1
x-5y=4

Answer 1

4x=-1+3y
x=(3y-1)/4

(3y-1)/4-5y=4
(3y-1)/4-20y/4=4
(3y-1-20y)/4=4
(-17y-1)/4=4
-17y-1=16
-17y=17
y=-1

x-5y=4
x=4+5y
x=4+5*(-1)
x=-1