Qhat is 4c - 11 - 5c + 17 what are the coefficients

Suppose a pendulum is l meters long. the time,t,in seconds that it tales to swing back and forth once is given by t=2.01

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.

The suare root of 9x plus 7 plus the square rot of 2x equall to 7