Answer :
-3x - 3y=9 (1)
+ 3x - 4y = 5 (2) First, Add equation 1 to equation 2
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0 - 7y = 14 Then, isolate y
y= 14/ -7 = -2
Replace y in equation 2 or equation 1. Let's replace in equation 2
3x - 4(-2)= 5
3x + 8 = 5 Isolating 3x
3x = 5-8
3x = -3 Isolating x
x = -3/3= -1
Answer: y= -2 and x=-1