-6y + 15 = -21

help me out please

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.

Can someone pls ! pls answer all. no explanation needed..

Ineed in figuring out this problem.