SOLUTION: Hi I need to construct an algebraic expression for the following: I am really bad at algebra! I'd really appreciate help with this one as I have been trying to figure it out for

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Question 877564: Hi
I need to construct an algebraic expression for the following: I am really bad at algebra! I'd really appreciate help with this one as I have been trying to figure it out for ages.........
John has only 20 cent coins and 50 cent coins in his wallet. He has three more 50 cent coins than 20 cent coins, and their total value is €2.90. How many 20 cent coins does John have?
Kathy

Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
x is how many 20 cent coins
y is how many 50 cent coins
y=3+x, three more 50 cent coins than 20 cent coins.

The money units sum is 20x%2B50y=290, simplified as 2x%2B5y=29.
Substitute for y.
2x%2B5%283%2Bx%29=29
2x%2B15%2B5x=29
7x%2B15=29
7x=14
highlight%28x=2%29, highlight%28y=5%29.