Sixteen is seven plus three times a number

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

Jack did 3/5 of all problems on his weekend homework before sunday. on sunday he solved 1/3 of what was left and the last 4 problems. how many problems were assigned for the weekend?

Write the equation in logarithmic form e^x=403.429