Question

I need help please my home work not to sure how to do it

Answer 1

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

Answer 2

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.