The point-slope form:

m - slope
We have the slope m = 2 and the point (6, 1). Substitute:

Answer:
32 units
Step-by-step explanation:
Easy way to get the answer, get your handy calculator and do 387*.75 = 290.25
Perimeter represents the height of the parallelogram
The numbers 1 to 72 add up to (1+72) x 72/2 = 73 x 36 = 2628
If we take away what Josh got we have 2628 - 2521 = 107
Pages in a book are odd on the first side and even on the second, so pages 11 and 12 are on the same sheet.
107 / 2 = 53.5 so the missing page had 53 on one side and 54 on the other side.
The remaining pages would have been numbered 1, 2, 3, ..., 51, 52, 55, 56, ... 71, 72