How to work out the problem

Question

 

7x+5y=-23 and -3x+y=13?

Answer 1

7x +5y = -23 -------(1)

-3x + y =  13 -------(2)

Multiply the equation (2) with -5

-3x + y =  13  × -5

15x - 5y = -65

Now add equation (1) and resultant equation to eliminate y

7x + 15x + 5y + (-5y) = -23 + (-65)

22x = -88

x = -4

Now substitute x = -4 in equation (1)

  7(-4) + 5y = -23

  -28 + 5y = -23

   5y = 5

    y = 1

The values of x and y are   -4,1 respectively