Answer:
Speed of river's current = 5 mph
Step-by-step explanation:
Let 'd' be the distance covered
Let x be the speed of the rivers current
Speed upstream = 15-x
speed downstream = 15+x
Time = distance / speed
time upstream = 
time downstream = 
the ferry trip upstream takes twice as long as its return trip downstream
= 
divide both sides by d
= 
cross multiply


Add 2x on both sideds

subtract 15 from both sides and divide by 3

x=5
Speed of river's current = 5 mph
Answer:
-x+11
Step-by-step explanation:
am not sure if this is correct but
2x-3x=-x
-7+18=11
-x+11
Answer:2516 pounds
Step-by-step explanation:
find the difference in gallons and the difference in the weights
46 - 14 = 32 gallons
2399 - 2191 = 208 pounds
so 32 gallons of gas weighs 208 pounds
find weight per pound: 208 pounds / 32 gallons = 6.5 pounds per gallon
round to 6.5 pounds per gallon
64 gallons - 46 gallons = 18 gallons
18 gallons x 6.5 pounds per gallon = 117 pounds
2399 + 117 = 2516 weight of plane with 64 gallons
Answer:
162
Step-by-step explanation:
Since the ratio is 3, the terms are 3 times the term before.
So the answer is 2*3^4 = 162