I am assuming you meant:
y=2x/5+9
If so:
A parallel line must have the same slope. The line is of the form:
y=mx+b where m=slope, in this case 2/5
So the parallel line will be of the form:
y=2x/5+b where b is the y-intercept.
There are infinitely many solutions as any line with the same slope is parallel to the original line. However the y-intercept can be any real number, that is why there are infinitely many solutions...Any value of b in the line we found above will still be parallel to the original line...
