two similarities between constructing a perpendicular line through a point on a line and constructing a perpendicular through a point off a line

Aline passes through the point (2, -4) and has a slope of 0, what is the equation of the line? plz fast

If the cost to mail a package is an initial $5 and $0.28 for every pound the total cost to mail a package was $11.27, how much did the package weigh?

Aculture started with 4,000 bacteria. after 5 hours, it grew to 5,200 bacteria. predict how many bacteria will be present after 19 hours. round your answer to the nearest whole number.