HELP ME PLEASE IT'S URGENT

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

The position of a moving particle is given by the position function: f(t)=-9t-t^2-0.2t^3+0.1t^4 0 a. at what time does the particle reverse direction? b. when is the displacement positive? (round one decimal place and answer in interval notation) c. when is the displacement negative? (round one decimal place and answer in interval notation) d. when is the particle’s acceleration positive? (round one decimal place and answer in interval notation) e. when is the particle’s acceleration negative? (round one decimal place and answer in interval notation)

Find the length of the radius of a circle with the center at -7+2i and a point in the circle at 33+11i