5 x + 3 y = 27
A = 100 + 10 x + 6 y
A = 100 + 2 × ( 5 x + 3 y )
A = 100 + 2 × 27
A = 100 + 54
A = 154
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4 + 2 x + 7 y = 15
B = 20 + 10 x + 35 y
B = 5 × ( 4 + 2 x + 7 y )
B = 5 × 15
B = 75
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x + 5 y = 23
C = 3 x + 15 y - 42
C = 3 × ( x + 5 y ) - 42
C = 3 × 23 - 42
C = 69 - 42
C = 27
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3 x - 2 y - 4 = 18 ⇒ 3 x - 2 y = 18 + 4 ⇒ 3 x - 2 y = 22
D = 12 x - 8 y
D = 4 × ( 3 x - 2 y )
D = 4 × 22
D = 88