Someone please help I failed this test so many times

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

What is the number 321,000,000 in scientific notation? also what is the number? ?

Give the equations of two different lines that are perpendicular to the line 3x + 4y = 7.