MATH  Can someone please help!
posted by KiKi on .
Suppose you are in the market for a new home and are interested in a new housing community under construction in a different city.
a) The sales representative informs you that there are two floor plans still available, and that there are a total of 70 houses available. Use x to represent floor plan #1 and y to represent floor plan #2. Write an equation that illustrates the situation.
b) The sales representative later indicates that there are 4 times as many homes available with the second floor plan than the first. Write an equation that illustrates this situation. Use the same variables you used in part a.
I think the answers are x+y=70
x+y(4)=70
but then I also have to solve using the substitution method and I don't get that one!

x + y = 70, IF x = number of of homes with floor plan #1 and y = number of homes with floor plan #2
Then y = 4x
Now use your substitution method.