2x + 5y = 20 dan x + 4y = 10 berapakah 3x + 2y ?
Matematika
Saadahrus
Pertanyaan
2x + 5y = 20 dan x + 4y = 10 berapakah 3x + 2y ?
2 Jawaban
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1. Jawaban Anonyme
Bab Persamaan Linear
Matematika SMP Kelas VIII
x + 4y = 10
x = 10 - 4y
2x + 5y = 20
2(10 - 4y) + 5y = 20
20 - 8y + 5y =20
-3y = 20 - 20
y = 0
x = 10 - 4y
x = 10 - 4 . 0
x = 10
3x + 2y = 3 . 10 + 2 . 0 = 30 -
2. Jawaban dendylenskii
2x + 5y = 20 | * 4
x + 4y = 10 | * 5
8x + 20y = 80
5x + 20y = 50
------------------- -
3x = 30
x = 30/3
x = 10
2(10) + 5y = 20
5y = 20-20
y = 0/5
y = 0
3x + 2y
3(10) + 2(0)
30 + 0
Jawaban = 30