Question 29728
Solve the 1st equation for "y", as follows:
5x-y=1
Add "y" to both sides of the equation to get:
5x=y+1
Subtract "1" from both sides to get:
y=5x-1
Now, substitute that value of "y" into the 2nd equation, as follows:
3x+5x-1=1
8x=2
x=2/8
x=1/4
Substitute that value of "x" into "y=5x-1" as follows:
y=5(1/4)-1
y=(5/4)-(4/4)
y=1/4
So the solution for the two original equatins is 
x=1/4, y=1/4
You might check that answer in the two original equations.
Cheers,
Stan H.