Question

3(x+y)-4(x-y)=5
4(x+y)-3(x-y)=9​

Answer 1

Ответ:

3(x+y)-4(x-y)=5

4(x+y)-3(x-y)=9

3x+3y-4x+4y=5

4x+4y-3x+3y=9

-x+7y=5

x+7y=9

-x+7y=5

x=9-7y

-(9-7y)+7y=5

-9+7y+7y=5

14y=5+9

14y=14

y=14÷14

y=1

x=9-7×1

x=2

ответ:

(x;y)=(2;1)