Let b and s be the velocity of the boat and stream respectively....
3(b-s)=27
b-s=9
b=9+s we will use this in the second equation....
2(b+s)=30
b+s=15, now use b found above in this to get:
9+s+s=15
2s+9=15
2s=6
s=3, and since from earlier b-s=9, b=9+s so
b=12
So the speed of the boat is 12mph and the stream is 3 mph
Step-by-step explanation:
4x2 - 25b2
We can solve it by the squares so
(2x - 5b) (2x + 5b)
2) x2 - 81
The same case is here so
(x - 9) (x + 9)
The area of the figure is 19.
Answer:
0.3 per year
Step-by-step explanation:
Number of newborn per year: 200*0.5 = 100
Number of death per year: 200*0.2= 40
So, the difference between birth and death = 100-40 = 60 (people)
and the growth rate during the year is: 60/200 = 0.3
<em>Hope this answer will find you well. </em>