Factorize
3a⁴+18a²-21-2b-3b²​

Find the area of the regular hexagon if a side is 20 cm.

Is the power produced directly proportional to the wind speed, give reasons for your answer?

Aroulette wheel has 38 slots in which the ball can land. two of the slots are green, 18 are red, and 18 are black. the ball is equally likely to land in any slot. the roulette wheel is going to be spun twice, and the outcomes of the two spins are independent.the probability that it lands one time on red and another time on black in any order is(a) 0.5 (b) 0.25 (c) 0.4488 (d) 0.2244