tolong ya pakai cara

Bab Kesebangunan
Matematika SMP Kelas VII

8/(8 + 4) = 12/(12 + x)
8 (12 + x) = 12 . 12
96 + 8x = 144
8x = 144 - 96
x = 48/8
x = 6

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8/(8 + 4) = y / (y + 8)
8 (y + 8) = y . 12
8y + 64 = 12y
12y - 8y = 64
4y = 64
y = 64/4
y = 16

maka, x = 6 dan y = 16