What's a simplified form of x-1+4+7x-3

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

Write the fraction or mixed number and the decimal shown by the model

What are the triple angle formulas? is it related to double angle identities?