Please help with math:).

Identify an equation in point slope form for the line perpendicular to y=3x+5 that passes through (4,-1)

Julia bought 7 hats a week later half of all her hats were destroyed in a fire. there are now only 12 hats left with how many did she start

Find the volume v of the solid obtained by rotating the region bounded by the given curves about the specified line. y = x â’ 1 , y = 0, x = 5; about the x-axis v = sketch the region. sketch the solid, and a typical disk or washer.