Question 220661
you were on the right track.
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you let x = number of houses with floor plan 1
you let y = number of houses with floor plan 2
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you had x + y = 38
you had 175000*x + 200000*y = 7200000
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you need to solve both these equations simultaneously.
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you can do it by substitution.
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take the first equation and solve for x or y.
either one will do.
I used x = 38-y
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substitute for x in the second equation to get:
175000 * (38-y) + 200000 * y = 7200000
this expands to be:
175000 * 38 - 175000 * y + 200000 * y = 7200000
this simplifies to:
6650000 + 25000y = 7200000
subtract 6650000 from both sides of this equation to get:
25000y = 550000
divide both sides by 25000 to get:
y = 22
that makes x = 16 because 22 + 16 = 38
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