Answer:
He drove the rest of the trip at 30 miles per hour
Step-by-step explanation:
The rule of the distance is D = v × t, where
∵ It is 170 miles from Bruce's house to the city where his brother lives
∴ D = 170 miles
∵ He drove for 2 hours at 55 miles per hour
∴ t1 = 2 hours and v1 = 55 miles/hour
→ By using the rule above find the distance of this part of his trip
∴ D1 = 55 × 2 = 110 miles
∵ The rest of the trip took 2 hours
∴ t2 = 2 hours
∵ D = D1 + D2
→ Substitute the values of D and D1 to find D2
∴ 170 = 110 + D2
→ Subtract 110 from both sides to find D2
∴ 60 = D2
∴ D2 = 170 - 110 = 60 miles
∵ The rest of the trip is 60 miles
∵ It took 2 hours
∵ D2 = v2 × t2
∴ 60 = v2 × 2
→ Divide both sides by 2
∴ 30 = v2
∴ v2 = 30 miles/hour
∴ He drove the rest of the trip at 30 miles per hour