Answer :
multiply first equation by -5 and 2nd by 2, add them
15x+20y=-100
2x-20y=32 +
17x+0y=-68
17x=-68
divide both sides by 17
x=-4
the x value is -4
15x+20y=-100
2x-20y=32 +
17x+0y=-68
17x=-68
divide both sides by 17
x=-4
the x value is -4