5x-3y=-9 x=? y=? x-4y=5

Question

5x-3y=-9 x=? y=? x-4y=5

Answer 1

{5x-3y=-9

{x-4y=5 =>{х=5+4у

5(5+4у)-3у=-9

25+20у-3у=-9

17у=-34

у=-2

х=5+4×(-2)=-3

Ответ: х=-3; у=-2