PLZZ HELP DO QUESTIONS 2,3, and 4, or atleast some of them i have question 1 done

In the following situation, determine whether you are asked to determine the number of permutations or combinations. then do the calculation how many ways are there to pick a starting five from a basketball team of twelve members? a. permutation; ps - 2520 b. combination; 1c, - 792 c. combination: 2cs - 2520 d. permutation; ps - 95040

How to find the exponential function y=ca^x, with points (1,2) and (2,1)

The ph level of a blueberry is 3.1 what is the hydrogen-ion concentration [h+] for the blueberry