If (x+2) and (x-1) are factors of ax cube + 2x -3x square -bx - 4 then the value of a +b is what

Look at this pattern ; 1,4,9, number 10000 belongs in this pattern . what’s the place of this number?

The probability that an adult possesses a credit card is .70. a researcher selects two adults at random. by assuming the independence, the probability that the first adult possesses a credit card and the second adult does not possess a credit card is:

Someone me! if you’re smart you can solve this!