rob owns a construction company and is placing a 7 line ad in the paper for a heavy equipment operator the following piecewise function gives the price of the x-line ad.c(x)= {25 when x 5 20+7(x-5) when x>5a.) what is the cost of the first 5 lines?b.) what is the cost of the first 5 lines if rob purchases more than 5 lines?c.) How much more is a 6 line add than a 5 line ad?