d + q = 40 -----> d = 40 - q
10d + 25q = 490 (equation multiplied by 100 to get rid of those pesky decimals)
10(40 - q) + 25q = 490
400 - 10q + 25q = 490
15q = 90
q = 6
d = 40 - 6
d = 34
Esthela C.
asked 08/15/18
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