Question

Translate problem into an equation and solve.

Thiago and Brandon are driving away from each other in opposite directions. If Brandon’s speed is 70 mph and Thiago's speed is 80 mph, how many hours will it be before the two are 225 miles apart?

Answer 1

Answer: 1.5 hours

Explanation:

If Thiago and Brandon move in opposite directions at speeds of 80mph and 70mph then after 1 hour Thiago will have traveled 80 miles and Brandon will have traveled 70 miles.

Since they are in opposite directions then the distance is from

`70 + 80 = 150\ miles`

Then we know that after t hours have elapsed they are 225 miles

Then we pose the following equation

`80t + 70t = 225`

Now we solve for t

`(80 + 70) t = 225`

`150t = 225\\\\t=(225)/(150)\\\\t=1.5\ hours`