M m m m basically what does x equal i guess i dont know for 3x+4

In what form is the following linear equation written y=9x+2

Kapil needed to buy a long wooden beam. he went to two sawmills that each charge an initial fee plus an additional fee for each meter of wood. the following equation gives the price (in dollars) of a wooden beam from the first sawmill as a function of its length (in meters). p = 5+20xp=5+20x

Complete the equation of the line through (−10,3) and (−8,−8). use exact numbers.