Question

-3x -4y = 20 x - 10y =16 if (x, y) is the solution to the system of equations above what is the value of x?

Answer 1

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