First off, let's keep in mind that perpendicular lines have negative reciprocal slopes, hmmm so what's the slope of y = 2x + 5?
well, notice, that equation is in slope-intercept form, thus

.

so, we're really looking for the equation of a line whose slope is -1/2 and runs through 1,4.
I pretty sure the answer is 134217728000000000000/17
The answer is 15 i believe