If I give my brother 5 dollars, then we will have the same amount of money. If instead, he gives me 12 dollars, then I'll have twice as much money as he will have. How much money does my brother currently have (in dollars)?
If I give my brother 5 dollars, then we will have the same amount of money. If instead, he gives me 12 dollars, then I'll have twice as much money as he will have. How much money does my brother currently have (in dollars)?
Let M = my original amount
Let B = brother's original amount
(M – 5) = (B + 5) (eq 1)
(M + 12) = 2 • (B – 12) = 2B – 24 (eq 2)
Subtract (eq 1) from ((eq 2) M + 12 = 2B – 24
M – 5 = B + 5
17 = B – 29
B = 46
and btw M = (B + 10) = 56
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