Answer:
Speed of boat in still water = 11 miles per hour.
Step-by-step explanation:
Speed = distance / time
or
Distance= Speed * time
Let s be speed of the boat upstream and r be the speed of the river.
Then
Upstream speed= s- r = 60/6= 10 miles per hour
Downstream speed= s+r= 72/6= 12 miles per hour
Therefore
s-r= 10--------- equation A
s+r= 12--------- equation B
Adding equation A and Eq. b
s-r= 10--------- equation A
<u>s+r= 12--------- equation B </u>
<u>2s = 22 </u>
<u />
or
s= 22/2= 11 miles per hour.
Speed of boat in still water = 11 miles per hour.
Answer: 4
Step -by-step :
7+7+7=21
5+12+a=
17+a
21-17=4
Answer:
Yes, twice
Step-by-step explanation:
The equation will intersect the x-axis when y = 0, so we have
x² - 4x = -3 now solve this quadratic for x...
x² - 4x + 3 = 0
factor...
(x - 3)(x - 1) = 0,
so at x = 1 and x = 3, the function crosses the x-axis
See the graph below
