Answer:
Return trip travel time: 7h
Step-by-step explanation:
Let d be the distance.
Index 1 refers to initial trip, index 2 refers to the return trip.
v1=70mi/h
v2=40mi/h
t2=t1+3h, or t1=t2-3h (travel times)
d=v1×t1=v2×t2
v1×(t2-3)=v2×t2
v1 t2 -3 v1=v2 t2
v1 t2 - v2 t2=3 v1
t2(v1-v2)=3v1
t2=3v1/(v1-v2)
Or
t2=3×70/(70-40)=3×70/30=7h
Answer:
9a-7
Step-by-step explanation:
8a-6+a-1
Collect like terms
8a+a-6-1
= 9a-7
Answer:
2.52
Step-by-step explanation:
Answer:
you could just count them
