tentukan himpunan subtitusi dan eliminasi x+y=4 2x+3y=16

x + y = 4 |.3| 3x + 3y = 12
...................... 2x + 3y = 16
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......................... x = -4

x + y = 4 => -4 + y = 4 => y = 8

HP = {(-4, 8)}