Answer:
A
Step-by-step explanation:
note that i = 
given
- 1 + 2i
= - 1 + 
= - 1 + 
Answer:
Mrs. Stern washed more
laundry still needs to be washed.
Step-by-step explanation:
Total amount of laundry: 


of the laundry still needs to be done.
Mrs. Stern washed
of the laundry.
Her son washed
of the laundry.
Mrs. Stern washed more laundry than her son.
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