How do you determine sample size needed for a factorial design reddit?

Write an equation in point-slope form for the line through the given point that has the given slope (-2,-7); m=-3/2

How many liters of peroxide should be added to 12 liters of an 8% peroxide solution so that the resulting solution contains 16% peroxide?   original added new amount of peroxide 0.96 liters x 0.96 + x amount of solution 12 liters x 12 + x 0.18 liter 1.14 liters 1.92 liters 2.10 liters

Explain how you can show five less than a number using algebraic expression