Well, here goes.
Boatesville is 50.4km far from Stanton (when you do 63×4/5).
A bus needs to travel 8km more to get to Boatesville. Difference is your answer.
50.4km-8km= bus has travelled 42.4km
B = 0.5A + 30
C = 1.5A + 20
If B = C, that means we can set the two equations equal to each other.
0.5A + 30 = 1.5A + 20
A = 10... Plug that into one of the equations to find B or C (they are the same)..
B = 0.5 * 10 + 30 = 35
35 + 35 + 10 = 80 total.
Use Pythagorean theorem
so, a^2 + b^2 = c^2
400-144 = b^2
find the square root of 256
= 16
