Someone please explain how to do this, like the steps to get the answers?? Please!!

What is the simplified form of (3.25x10^3)(7.8x10^6) written in scientific notation?

(x-5)1/2+5=2 what is a possible solution?

Aparticular telephone number is used to receive both voice calls and fax messages. suppose that 25% of the incoming calls involve fax messages, and consider a sample of 25 incoming calls. (a) what is the expected number of calls among the 25 that involve a fax message?