Question 979300
d + r = 13 --> r = 13-d
1.11r + 0.95d = 13.15
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Multiply by 100
111r + 95d = 1315
Sub for r
111*(13-d) + 95d = 1315
1443 - 111d + 95d = 1315
-16d = -128
d = 8
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r = 5