Part (a)
Answer: 60w+350
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Work Shown:
For the first account, the expression 25w+125 would represent how much is in this account after w weeks. The 125 is the amount he starts with, while adding on 25w represents adding 25 dollars per week, and w is the number of weeks.
For instance, if w = 2 weeks go by, then he's added on 25*w = 25*2 = 50 dollars on top of the 125 so far.
For the second account, the expression 35w+225 represents how much is in the account after w number of weeks pass by.
Adding the two expressions leads to
(25w+125)+(35w+225)
(25w+35w)+(125+225)
60w+350
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Part (b)
Answer: 1250 dollars
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Work Shown:
We'll use the result from part (a)
Plug in w = 15 to find out how much total money he has in the two accounts after 15 weeks.
60w+350
60*15+350
900+350
1250
