1).
3x – 2 = 7
3x = 7 + 2
3x = 9
x = 9/3
x = 3
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2).
3 (x – 1) + x = -x + 7
3x – 3 + x = -x + 7
4x – 3 = -x + 7
4x + x = 7 + 3
5x = 10
x = 10/5
x = 2
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3).
3n + 3 = 12
3n = 12 – 3
3n = 9
n = 9/3
n = 3
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4).
3/4z = 18
z = 18 ÷ (3/4)
z = 18 × 4/3
z = 72/3
z = 24
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5). Misal;
Ibu = x
x = 3y
Danu = y
x – y = 30
Umur Danu
3y – y = 30
2y = 30
y = 30/2
y = 15
Umur Ibu
x – y = 30
x – 15 = 30
x = 30 + 15
x = 45