Question 1016199
cindy has 17 bills in her wallet. some are $10 bills and some are $20 bills. the total value of the bills are $230. how many $10 bills and how many $20 bills does she have?
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t = # of 10's
w = # of 20's
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t + w = 17
10t + 20w = 230 --> t + 2w = 23
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t + w = 17
t + 2w = 23
---------------- Subtract
-w = -6
--> 6 $20's
11 $10