1) Unanswered (Sorry)
2) Find the cost of a four-line ad
[tex]x = 4 \\Therefore,\\c(4) = 30[/tex]
3) Find the cost of a ten-line ad
[tex]x = 10\\Therefore,\\c(10) = 30 + 5(x - 4)\\c(10) = 30 + 5x - 5(4)\\c(10) = 30 + 5x - 20\\c(10) = 30 + 5(10) - 20\\c(10) = 30 + 50 - 20\\c(10) = 60[/tex]
