In this equation:
35x + 26y = 70

I rearranged the terms to get y as function of x:
y = (70 - 35x) / 26

In book I'm reading it's rearranged differently:
y = - (35 / 26)x + 70 / 26

than I check in python with x set to 3:
>>> (70-35*3)/26
-1.3461538461538463
>>> -35/26*3+70/26
-1.3461538461538458

Why are the results slightly different? Other values of x gave identical results.