Solve by Substitution: 5x + 7y = 10 -3x + 14y = -6

So we have to solve 5x + 7y = 10, -3x + 14y = -6 by substitution, and we do this by, you guessed it, substituting!

5x + 7y = 10   --We first have to get x = something, so we can substitute x to find y.

/5    /5    /5    --Divide everything by 5

x + 7/5y = 2

   -7/5y     -7/5y   --Subtract 7/5y from both sides

x = -7/5y + 2

-3x + 14y = -6

-3(-7/5y + 2) + 14y = -6      --Substitute x in

21/5y -6 + 14y = -6

         +6             +6

4 1/5y + 14y = 0

y = 0

5x + 7(0) = 10       --Now put in y to find x

5x = 10

x = 2

So y = 0 and x = 2.

Let's check it:

-3(2) + 14(0) = -6

-6 = -6  ✔

I like the way you add the "check' to your answers, NinjaDevo......it really brings it home that your solutions are correct......3 points from me!!!

Thanks CPhill.