Question 868905
5x+9y=-8

y-x=10
y=x+10
substitute y

5x+9(x+10)=-8

5x+9x+90=-8

14x=-98
/14
x=-7

plug x in y-x=10

y-(-7)=10
y+7=10
y=10-7
y=3
x=7,y=3