No 19 tlg bantuin ya kaa mksh
Matematika
geviraaline
Pertanyaan
No 19 tlg bantuin ya kaa mksh
1 Jawaban
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1. Jawaban jpallo
½ a - ¼ b = 2 (x 4) ===> 2a - b = 8
1/5 a + 1/3 b = 6 (x 15) ==> 3a + 5b = 90
2a - b = 8 x 5 ===> 10a - 5b = 40
3a + 5b = 90 x 1 ===> 3a + 5b = 90
------------------- +
13a = 130
a = 10
2a - b = 8 ===> 2(10) - b = 8 ==> b = 12
Jadi utk: 2a - 3b = 2 (10) - 3 (12) = 20 - 36 = -16 ( C )
semoga jelas dan membantu ya