What is the separation method of blood?

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

Can someone me and plz do the problem

What is the expression in factored form? -x^2 + 3x + 28 a. (x-7)(x-4) b. -(x-7)(x+4) c. (x+4)(x+7) d. -(x-4)(x+7)