1. x = 5 - 1/2y
2. x = 7 - 3/2y
Объяснение:
1. 3(x+y)+(x-y)=20
3x+3y+x-y=20
4x+2y=20
4x=20-2y
x = 5 - 1/2y
2. 5(x+y)-(x-y)=28
5x+5y-x+y=28
4x+6y=28
4x=28-6y
x = 7- 3/2y
1. x = 5 - 1/2y
2. x = 7 - 3/2y
Объяснение:
1. 3(x+y)+(x-y)=20
3x+3y+x-y=20
4x+2y=20
4x=20-2y
x = 5 - 1/2y
2. 5(x+y)-(x-y)=28
5x+5y-x+y=28
4x+6y=28
4x=28-6y
x = 7- 3/2y