Divide 3/4 by 1/8 and you should get 6 hurdles.
2x + 5 = 3x - 45 [alternate interior angles]
3x - 2x = 5 + 45
x = 50
4y - 1 + 2x + 5 = 180 [supplementaly angles]
4y + 2(50) + 4 = 180
4y + 100 = 176
4y = 76
y = 19
Suppose that this person drives at r mph going to the mountains, and gets there in 12 hours. Returning, this person drives at (r+20) mph and gets home in 8 hours. We don't know the distance yet, but can solve for the initial speed, r, by setting
d = 12r = (r+20)(8). Solving for r, r=40 mph (going) and (40+20)mph = 60 mph (returning. Since d=12 r, d = (12 hrs)(40 mph) = 480 miles (answer).
-2 | 2 4 2 8 8
. | . -4 0 -4 -8
-------------------------------
. | 2 0 2 4 0
which translates to
