SMP D/UN/2015 penyelesaian

4x - 3y = 12 | 1 | 4x - 3y = 12
2x + y = 16 | 2| 4 x +2y = 32.
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-5y = -20
y = 4

2x + y = 16
2x + 4 = 16
2x = 16-4
2x = 12
x. = 6

a - 2b = 6 - 2(4)
= - 2