Expert: Scott A Wilson - 1/21/2012

Question
Ok so I have tried this tons of way and I keep getting decimal answers or a too high of an answer.
7x+2y=6
3x-4y=19

can you help me on this I figured out x but cant find y..? I appreciate it.

Answer
Looking at 7x + 2y = 6, we can subtract 2y from both sides and get 7x = 6 - 2y.
We can then divide both sides by 7, giving x = 6/7 - 2y/7.
This can be put into the second equation, giving 3(6/7 - 2y/7) - 4y = 19.
Multiplying the 3 through gives 18/7 - 6y/7 - 4y = 19.

Note that the multiplier on y are -6/7 and -4, which combine to -34/7.
Also note that 19 = 133/7, so 19 - 18/7 = 133/7 - 18/7 = (133 - 18)/7 = 115/7.
Thus, we have -34y/7 = 115/7, so -y = 115/34.  Putting this back in the 1st equation for y will allow that equation to be solved for x.