Simplify the following number by using the imaginary number i square root of -19

Which expression shows the sum of the polynomials with like terms grouped together

Tim's phone service charges $26.39 plus an additional $0.21 for each text message sent per month. if tim's phone bill was $31.64, which equation could be used to find how many text messages, x, tim sent last month?

Ithink i know it but i want to be sure so can you me out ?