Question

Решите систему уравнений

Answer 1

2x-y=4
x+y=5

2x-y=4
x=5-y

2(5-y)-y=4
10-2y-y=4
-3y=-6
y=-6:(-3)
y=2
x=5-2=3

3x+y=13
x-y=3

3x+y=13
x=3+y

3(3+y)+y=13
9+3y+y=13
4y=4
y=4:4
y=1
x=3+1=4