Find the values of x for which the denominator is equal to zero for y= x-3/x^2 - 1

Aparallel system functions whenever at least one of its components works. consider a parallel system of n components, and suppose each component works independently with probability 0.5. find the conditional probability that component n works given that the system is working

If (x-2) 2= 49, then x could be a. -9 b. -7 c.- 2 d. 5 e.9

Asap! i'm not good math and i'm lost.