(x+3) (x-4) (x+5) is identical to x^3 + ax^2 - 17x + b
What is the value of a and b?

Successful implementation of a new system is based on three independent modules. module 1 works properly with probability 0.96. for modules 2 and 3, these probabilities equal 0.95 and 0.90. compute the probability that at least one of these three modules fails to work properly.