SOLUTION: 0.60x+$2y=$200 x+y=172 Please explain your steps. I don't know how to solve systems of linear equations, so please explain for whatever method you chose.

Algebra ->  Coordinate Systems and Linear Equations  -> Lessons -> SOLUTION: 0.60x+$2y=$200 x+y=172 Please explain your steps. I don't know how to solve systems of linear equations, so please explain for whatever method you chose.      Log On


   

Question 1013130: 0.60x+$2y=$200
x+y=172
Please explain your steps. I don't know how to solve systems of linear equations, so please explain for whatever method you chose.
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
First, you should try to simplify the money equation if possible to have whole number or integer coefficients.

0.6x%2B2y=200
%283%2F5%29x%2B2y=200
Simply multiply left and right members by 5 to clear the denominator.
3x%2B5%2A2y=5%2A200
3x%2B10y=1000

This means your system of equations is system%283x%2B10y=1000%2Cx%2By=172%29.
(You probably took a less than ideal example, but no matter - it can still be used).

Do you understand how to begin solving the system using Substitution?
Solve either equation for one variable in terms of the other, and substitute into the other equation; and solve that for the single variable...

More than one way to start, but try to do what seems easier.
y=172-x
-
3x%2B10%28172-x%29=1000
3x%2B1720-10x=1000
-7x%2B1720=1000
-7x=1000-1720
7x=1720-1000
7x=720
highlight%28x=720%2F7%29-----unreduced but you use in whatever way you want or need.

Now, what is y?
y=172-x
y=172-720%2F7
...whatever the final form or value may be.