Explain how to find the difference between 9^10/9^11 and 9^11/9^10

Two planes leave an airport at the same time, one flying east, the other flying west. the eastbound plane travels 20 mph slower. they are 1600 mi apart after 2 hr. find the speed of each plane.

Find the directions in which the function increases and decreases most rapidly at upper p 0p0. then find the derivatives of the function in these directions. f(x,y)equals=x squared plus xy plus y squaredx2+xy+y2, upper p 0p0left parenthesis 1 comma negative 4 right parenthesis

Me i'm timed ! a. -2 to 1 b. -1.5 to 0.5c. 0 to 1d. 0.5 to 1.5