How can I figure out two possible points for each vertex mathematically?

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?

Find measure angle 1 and measure angle 3 in the kite the diagram is not drawn on the scale

The equation line of cd is y=-2x-2. write an equation of a line parallels to line cd in slope-intercept form that contains point (4,5)