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
3*|2-7| = 3*|-5|......absolute values are positive even when they say negative.
so 3*| -5 | = 3 * 5 = 15
It wouldn't play or else i would help
Take away 1 from either side so the equation becomes 63=3x then divide both sides by 3 so it becomes 21=x which is your answer (option A)
Answer:
4.615 in
Step-by-step explanation:
Triangle ABC and ABD are similar because they have two corresponding congruent triangles that is right angle and ∠A. Triangle ABC and BCD are similar because they have two corresponding congruent triangles that is right angle and ∠C. Therefore Triangle ABC, ABD and BCD are similar. Since they are similar, then their sides are proportional in length.
In triangle ABC, using Pythagoras theorem:
AC² = AB² + BC²
AC² = 12² + 5²
AC² = 144 + 25 = 169
AC² = 169
AC = √169 = 13 in
Using similar triangle for ΔABC and ΔABD:
