so to start this off you would add 9y to both sides of the equation and then you regroup it which gives you −2x=−25+9y and then you regroup the terms and get -2x=9y-25 and then you dived both sides by -2 and get x=9y-25/-2 then you simplify and so on
but at the end you should get x=-1 and y =3
