Which expression correctly represents “twice the sum of four and a number”?
2 (4 + n)
2 (4 n)
2 (4) + n
2 + (4 n)

An equation where variables are used to represent known values—function notation true or false

Tim's phone service charges $23.06 plus an additional $0.22 for each text message sent per month. if tim's phone bill was $28.56, which equation could be used to find how many text messages, x, tim sent last month?

Which function has the domain x> -11