Factorise fully
x2 - 42^2

Keith bought a soft drink for 4 dollars and 9 candy bars .he spent a total of 31 dollars .how much did each candy bar cost?

Find the solutions for a triangle with a =16, c =12, and b = 63º

The position of a moving particle is given by the position function: f(t)=-9t-t^2-0.2t^3+0.1t^4 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)