5x - 4y = 42 ------ (1)
x - 6y = 24 ----------(2), multiply eq. 2 by 5 we get
5x - 30y = 120 -----(3),
now use eq. (3) - (1),
5x - 30y = 120
-(5x - 4y = 42)
- 30y + 4y = 120 - 42,
-26y = 78, y = -78/26 = -3,
x = 24 + 6y = 24 + (6*[-3]) = 24 - 18 = 6,
x = 6, y = -3.
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