An airplane travels 400 miles against the wind in 4 hours and makes the return trip with the same wind in 2 hours find the speed of the wind.

400 miles 4 hours
X miles 2 hours

4x=400.2
4x=800
X=200

Or

400miles 4hours
X miles 6 hours

4x=400.6
4x=2.400
X= 600

First step is to get rid of the square root. remember that a square root is the same as raising to the (1/2) power. see below: multiply exponents per exponent rules to get: remember you subtract exponents from the denominator and add exponents in the numerator so: simplify further: so a is the correct choice. if you don't understand this google exponent rules and it will you understand. look at the image results.