show your work too please!

What is the value of x when x + 7 = 21?

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?

What fraction is equivalent to 0.46464646··· a. 46⁄999 b. 46⁄100 c. 46⁄99 d. 23⁄50