via the angle sum identity for cosine.
Answer:
not sure
Step-by-step explanation:
0 only 2
Answer:
2 km/h
Step-by-step explanation:
- distance = speed × time
- time = distance/speed
Let c represent the speed of the current of the river in km/h. Then the speed of the boat upstream is (10-c). In 3/4 hour, the distance traveled upstream is ...
... distance upstream = (3/4)·(10 -c)
The time taken to travel the same distance downstream is given as 3 hours. The speed in that direction is c, so we have ...
... 3 = distance upstream/c = (3/4)(10 -c)/c
Multiplying this equation by 4c, we get ...
... 12c = 3(10 -c)
... 15c = 30 . . . . . . . . add 3c
... c = 2 . . . . . . . . . . . divide by 15
The speed of the river current is 2 km/h.
Answer:
x = 2
Step-by-step explanation:
Note that 25 = 5² , then
= 5²
Since the bases on both sides are 5 then equate the exponents
6 - 2x = 2 ( subtract 6 from both sides )
- 2x = - 4 ( divide both sides by - 2 )
x = 2
