Expert: Scott A Wilson - 12/29/2010

Question
how can i solve
5x+300y=178
4x+500y=197 in substitution method?

Answer
Solve the first equation for y,  This means to 1st, subtract 5x from both sids.
This gives 300y = 178 - 5x.

After that, divide both sides by 300, giving y = (178-5x)/300.

Putting this in the second equation for y gives 4x + 500(178-5x)/300 = 197.
That reduces to 4x +l 890/3 - 25x/3 = 197.

Subtracting 890/3 from both sides and combining terms gives -13x/3 = -299/3.
Multiplying both sides by -3/13 gives x = 23 since 13*23 = 299.

This can then be put back in the 1st equation to find y.
Once both values have been found, put them in the 2nd equation to check.
Note that I believe that y comes out to be 273/1300.