Mark M. answered • 06/24/15

Tutor

5.0
(243)
Mathematics Teacher - NCLB Highly Qualified

d = r · t

On the way there

d = r · 10

On the way back

d = (r + 18)7

The distance there and back is the same

10r = 7(r + 18)

10r = 7r + 126

3r = 126

r = 42

r + 18 = 60