Perhaps you mean "slope-intercept" form. Solve for y and reduce the fractions.
.. -8x -6 = 2y . . . . . . . . add 2y-6
.. y = -4x -3 . . . . . . . . . divide by 2
Your line in slope-intercept form is
.. y = -4x -3
Answer is 13 because the numbers are increasing though odd numbers that are also increasing if that makes sense.
It’s going from 4 > 9 > 16 > 25 > 36
so from 4-9 it adds 5 and from 9-16 it adds 7 and goes on so that’s it’s like
+5 > +7 > +9 > +11
sorry if it doesn’t make good sense