What is the value of x and y in the simultaneous equation 4x plus 3y equals -5 and 3x plus 5y equals -12?

4x + 3y = -5 (Eq 1) 3x + 5y = -12 (Eq 2) Multiply the first equation by 3 and the second by 4: 12x + 9y = -15 (Eq 3) 12x + 20y = -48 (Eq 4) subtract Eq 3 from Eq 4 gives 11y = -33 so y = -3 and x = (15 + 12)/3 =1 Check: (4 x 1) + (3 x -3) = 4 - 9 = -5 and (3 x 1) + (5 x -3) = 3 - 15 = -12 QED Subtract