Jika 3/(x+y)+2/(x-y)=2 dan 9/(x+y)-4/(x-y)=1, maka x^2-y^2=
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Pertanyaan
Jika 3/(x+y)+2/(x-y)=2 dan 9/(x+y)-4/(x-y)=1, maka x^2-y^2=
1 Jawaban
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1. Jawaban sandysuhendra
Misalkan
a = 1/(x+y)
b = 1/(x-y)
Shg
3a + 2b = 2... ×2 - > 6a + 4b = 4
9a - 4b = 1..... ×1 - > 9a - 4b = 1
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15a = 5 mk a = ⅓ atau (x+y) = 3
3(⅓) + 2b = 2
1 + 2b = 2
2b = 1 mk b = ½ atau (x-y) = 2
x²-y² = (x+y) (x-y) = 3 × 2 = 6