Encuentra la ecuación que corresponde a las siguientes raíces

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?

Solve the equation: x - 9 = -6 + 5 a. 21 b. 7 c. 14 d. 2

For the following equations, find the ratio of a to b. be sure to show all of your work. a. 3a = 6b b. 15a = 5b