Help math ASAP please please

Marcus needs to rewrite f(x) = x2 + 6x + 4 in vertex form.

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.

You are at a restaurant and owe $38 for your meal. you want to leave a 20% tip. how much will your tip be?