Answer:
The answer is A, a total of 12 students spend 31 or more hours online per month.
Step-by-step explanation:
From the hours of 31 to 65 there are twelve students.
To solve this problem, let us first assign variables. Let
us say that:
A = runner
B = cyclist
d = distance
v = velocity
time = t
The time in which the cyclist overtakes the runner is the
time wherein the distance of the two is the same, that is:
dA = dB
We know that the formula for calculating distance is:
d = v t
therefore,
vA tA = vB tB
Further, we know that tA = tB + 2, therefore:
vA (tB + 2) = vB tB
4 (tB + 2) = 14 tB
4 tB + 8 = 14 tB
10 tB = 8
tB = 0.8 hours = 48 min
Therefore the cyclist overtakes the runner after 0.8
hours or 48 minutes.
Answer:
Step-by-step explanation:
First we need to determine the equation of the boundary line.
The line has y-intercept of c=7 and slope 
.
The slope is given by y=mx+c.
We substitute the slope and intercept to get:
.
Since the lower half plane is shaded, with the boundary being a dashed line, the required inequality is
All this is, is plugging in numbers. Then taking the square root of it. The first one would be the square root of 6 squared - 4(5)(-3). That would simplify to the square root of 36+60. Then add the numbers to get the square root of 96. The square root of 96 is about 9.798. I hope that helped. If you still need help with the second one or with the rest of the formula (if there is one) just ask!
