Writing equations for substitution and elimination.

[Jsnxt32]

I am trying to complete a checkpoint for class and need a couple clues for the world problems. I always have a problem with word problems. It's about buying houses;
a. sales rep. states there 56 houses for sale with two floor plans available. x is floor plan one, y is floor plan two. what equation illustrates this?

Is it x + y = 56 ?

b. sales rep. states there are three times as many homes available with floor plan two versus floor plan one. what equation illustrates this?

Is is x = 3y - 56 ?

Use substitution to determine how many of each floor plan is available.

[Stranger_1973]

I agree with (a) but how did you get (b)? What was your reasoning?

[Jsnxt32]

Part b is just a continuance of part a. The sales rep showing the houses stated that there are three times as many homes available in floor plan two, then floor plan one. The two separate equations are to be combined and figured through substitution, this is in order to figure out how many of each house there is.

[Stranger_1973]

Okay. You have x=plan 1 and y=plan 2. You have plan 1 is 3*(plan 2). How did you get "plan 1 is 3*(plan 2) less 56"?

Use the variagles instead & plug them into "plan 1 is 3*(plan 2)" just like you did for "the sum of plan 1 and plan 2 is 56".