SOLUTION: Hi all, Ive got some pretty simple stuff here but cant seem to get the last few equations done. I just need to solve for x and y for the following equations. 1. 5x-2y = 1 2. 8x-

Algebra ->  Equations -> SOLUTION: Hi all, Ive got some pretty simple stuff here but cant seem to get the last few equations done. I just need to solve for x and y for the following equations. 1. 5x-2y = 1 2. 8x-      Log On


   



Question 199695: Hi all, Ive got some pretty simple stuff here but cant seem to get the last few equations done. I just need to solve for x and y for the following equations.
1. 5x-2y = 1 2. 8x-9y=79
If someone could please explain to me the correct working step by step to solving these sorts of equations I would be really grateful.
Thanks, -Nick.

Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
1. 5x-2y = 1
2. 8x-9y=79
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There's more than one way to do these, but with 2 variables, substitution is simple.
Solve one of the eqn for one of the variables, then substitute it into the other one.
5x-2y = 1 --> y = (5/2)x - 1/2
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8x-9y=79
8x - 9*(5x/2 - 1/2) = 79
16x - 9(5x-1) = 158
16x - 45x + 9 = 158
-29x = 149
x = -149/29
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Sub x into either eqn to find y
5x-2y = 1
5*(-149/29) - 2y = 1
-745 - 58y = 29
-58y = 774
y = -387/29