Name: joy

Who is asking: Student Level: Middle

Question: how do u solve problems using systems of equations?
~ finding x and y~

ex:

26 = 3x - 2y
42 = 4x + y

Hi Joy,

First you should look at the answer Harley gave to a similar question that we received a while ago.

For your system of two equations I would multiply the second equation by 2 so that the coefficient of y is 2. I made this choice because the coefficient of y in the first equation is -2. Thus the second equation become

2(42) = 2(4x + y) or 84 = 8x + 2y Thus the pair of equations can be written 26 = 3x -  2y
84 = 8x + 2y Now add the two equation to get 110 = 11x and thus x = 10 Finally substitute x = 10 into either of the two equations you started with and solve for y.

As a check you should take x = 10 and the value of y you found and substitute them into the other of the two equations to verify that the solution you found satisfies both equations.

Cheers,
Penny
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