word problem please help

Question

Luther started biking to the mall traveling 13 mph, after some time the bike got a flat so Luther walked the rest of the way, traveling 5 mph. If the total trip to the mall took 8 hours and it was 64 miles away, how long did Luther travel at each speed?

Answer 1

X=bike

Y=walk

1. X+y=8

2. 13x+5y=64

Solve equation 1 for x or y. X=8-y or y=8-x

Substitute one of those equations in equations 2.

13(8-y)+5y=64 or 13x +5(8-x)=64 and solve for the missing variable.

Distribute the 13 or the 5 and get the following, the simplify and solve:

104-13y+5y=64 or 13x+40-5x=64

104-8y=64 or 8x+40=64

-8y=-40 or 8x=24

Y=5 or x=3

Plug in the answers to make sure they work. If only solved for one variable plug into the first equation and solve for unknown.