the answer to your question there would be 12
Let V, be the rate in still water and let C = rate river current
If the boat is going :
upstream, its rate is V-C and if going
downstream, its rate is V+C,
But V = 5C, then
Upstream Rate: 5C - C = 4 C
Downstream rate: 5C+C = 6C
Time = distance/Rate, (or time = distance/speed) , then:
Upstream time 12/4C and
Downstream time: 12/.6C
Upstream time +downstream time:= 2h30 ' then:
12/4C + 12/.6C = 2.5 hours
3/C + 2/C = 5/2 (2.5 h = 5/2)
Reduce to same denominator :
5C = 10 and Rate of the current = 2 mi/h
Answer: 16t^6−40t^3+25 is the answer
first lets set the equation as a binomial *remember 2 binomial= trinomial*
so its going to look something like..........
(4t^3-5) (4t^3-5)
now we do the foil method so 4t^3* 4t^3= 16t^6 (add exponents)
do the same for the other terms:
4t^3*-5= -20t^3
-5*4t^3= -20t^3
-5*-5= 25
now the whole equation is...
16t^6-20t^3-20t^3+25 (combine like terms like -20t^3 and -20t^3)
therefor the answer is... 16t^6-40t^3+25
you add up to the origin then divide your welcome
