Time = 3 miles / (20 mph - wind velocity)
time = 2 miles / (20 mph + wind velocity)
3 miles / (20 mph + wind velocity) = 2 miles / (20 mph - wind velocity)
3/2 = (20 mph + wind velocity) / (20 mph - wind velocity)
1.5 = (20 mph + wv) / (20 mph -wv)
30 mph -1.5wv = 20 mph -wv
10 mph = 2.5 wv
wind velocity = 4 mph
The answer is A in both cases. Changing the units does not change the measurement, only the number representing the measurement. (Some numbers are easier to work with than others, which is why some units are preferred for certain measurements.)
Question 1.
A. <span>The surface area stays the same, but the number representing the surface area decreases.
Question 2.
</span><span>A. The surface area stays the same, but the number representing the surface area increases.
</span>
One piece at a time:
4(p+2) means 4 times everything inside the parentheses.
That's
4(p) + 4(2) = 4p + 8 .
3(2p-3) means 3 times everything inside the parentheses.
That's
3(2p) + 3(-3) = 6p - 9 .
Now add everything up:
4p + 8 + 6p - 9 .
Add all the p's together: 4p + 6p = 10p
Add all the plain numbers together: 8 - 9 = -1
The final result is: 10p - 1 .
