Find the average speed in mph for each journey
70 miles in 2 hours
115 miles in 1 hour 40 minutes
can someone give me the answer and explain how you got it

(rate) = (distance) / (time)

r = d/t

Solve for time.

t = d/r

Substitute.

t = (70 miles) / (70 miles/hour)

= (70/70) (miles/(miles/hour))

= 1 hour

Speed = distance / time     But be careful with the units and the errors.

With some simple algebraic rearangement    Time = Distance / Speed

If Distance = 70 miles and Speed = 70 miles / hour.

Time = 70 / 70  = 1 and the units stay consistent so that is 1 hour.

See below in bold.

Step-by-step explanation:

In 2 hours we travel 70 miles

By proportion, in 1 hour we travel 70/2 =  35 miles which is 35 mph.

1 hour 40 minutes = 1 2/3 = 5/3 hours.

In 5/3 hours we travel 115 miles so

In  1 hour we travel  115 / 5/3 miles

= 115 * 3/5 = 69 mph.

δabc ≅ δdcb by sas because

db ≅ ac . . given (side)

bc ≅ bc . . reflexive property (side)

∠dbc ≅ ∠ acb . . alternate interior angles where transversal bc crosses parallel lines bd and ac (included angle)