Answer:
no 2. cube a' will be smaller because it was multiplied by a fraction
no 3. c
Running 2 miles at 8:15 per mile takes 16:30 minutes.
Running 3 miles at 7:12 per mile takes 21:36 minutes.
The total running time is 16:30 + 21:36 = 38:06 minutes. That length of time after 6:52 am is 7:30:06 am.
You get home for breakfast at 6 seconds past 7:30 am.
Speed = Distance / Time
Distance = Speed*Time
For this problem, we should bear in mind that current speed has an impact on the boat speed...
for upstream, the boat goes against the current, and so its speed is
U = V - C
where V is the speed of the boat
C is the current speed
for downstream, it will be:
D = V + C
Convert the problem into mathematical equations:
4D + 3U = 116
3D + 4U = 108
4(V+C) + 3(V-C) = 116
4V + 4C + 3V -3C =116
7V + C = 116
3(V+C) + 4(V-C) = 108
3V + 3C + 4V - 4C = 108
7V - C = 108
Solving the equations:
7V + C = 116
7V - C = 108
14V = 224
V = 16km/hr —-> speed of boat
to get C:
7(16) + C = 116
C = 4km/hr
The equation for the perimeter of a rectangle:
P = 2L + 2W
We’re given P and L and asked to find W:
15x + 17y = 2(7/2x + 7y) + 2W
15x + 17y = 7x + 14y + 2W
2W = 8x + 3y
W = 4x + 3/2y
Answer is A.
