The given equations :
x + y = 1 (1)
5x + 3y = (-3) (2)
Multiply the equation (1) by 5
5(x + y) = 5 x 1
5x + 5y = 5 (3)
Subtract equation (3) and (2)
5x + 5y - (5x + 3y) = 5 - ( -3)
5x + 5y - 5x - 3y = 5 + 3
5x - 5x + 5y - 3y = 8
0 + 2y = 8
y = 4
Substitute the value of y = 4 in the equation (2)
5x + 3y = (-3)
5x + 3 (4) = (-3)
5x + 12 = (-3)
5x = -3 - 12
5x = -15
x = -15/5
x = (-3)
So, the solutions are : (x, y) = ( -3, 4)
Answer : (x, y) = ( -3, 4)