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Verified Answer :

  1. x+5y=8
        2x- 5y=1     What you do is find the number/variable that are the same( here is is the +5y and -5y. You want them to be opposites(-,+) so that they cancel each other out. if they are not opposites, then multiply one equation by a negative sign to change it. Cross out the 5y's. Now you can combine like terms-x+2x=3x, and 8+1=9, so now your equation will look like this:
    3x=9
    x=9/3
    x=3
    now take x=3 and plug it into the first equation to solve for y. x+5y=8, so 3+5y=8
    5y=8-3
    5y=5
    y=5/5
    y=1
    (3,1) are your answers.
    now do the same with the other problems.

To solve for all of your problems you could use substitution, elimination, or graphing. 
An example of substitution would be like this
X+5Y=8
X-X+5Y=8-X
5Y=8-X
5Y/5=8-X/5
Y=8-X/5
Now since we put our equation to solve for Y we can plug that equation into 2X-5Y=1.
2X-5(8-X/5)=1
2X-40+5X/-25=1
X=3

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