You find the rate of change which is (y2-y1)/(x2-x1)
(17.85-12.75)/(35-25)=0.51
(20.40-17.85)/(40-35)=0.51
So the rate is constant so this is a linear equation which is of the form:
y=mx+b where m is the slope just found and b would be a y-intercept if there was some initial value (which there isn't) when x=0 so we have:
y=0.51x
....
She received $32.13 so we can find how many miles she drove for work...
0.51x=32.13
x=63 miles drive for work...we are told that she drove a total of 134 miles that day...
Percent work related miles equals miles driven for work divided by total miles driven multiplied by one hundred. Mathematically:
p=100(63)/134
p≈47.0149%
p≈47% (to nearest one-hundredth of a percent)