Solve the following by elimination method

11x+15y+23=0 and 7x-2y-20=0

Let 11x + 15y + 23 = 0 be equation (1)

And 7x - 2y - 20 = 0 be equation (2)

Multiply equation (1) by 2:

22x + 30y + 46 = 0

Multiply equation (2) by 15:

105x - 30y - 300 = 0

Add equations (1) and (2):

22x + 105x + 30y - 30y + 46 - 300 = 0

127x - 254 = 0

127x = 254

x = 254/127

[x = 2]

Substitute x = 2 in equation (1) to find y:

11 (2) + 15y + 23 = 0

22 + 15y + 23 = 0

15y + 45 = 0

15y = - 45

y = - 45/15

y = - 3

Therefore, x = 2 and y = - 3.