The number of pens used varies directly with the number of pieces of paper needed. if 12 pens are used when 40 pieces of paper are needed, how many pens will be used when 240 pieces of paper are needed?

Given f(x) = 17-x^2what is the average rate of change in f(x) over the interval [1, 5]?

Suppose that one doll house uses the 1 inch scale, meaning that 1 inch on the doll house corresponds to 1/2 foot for life-sized objects. if the doll house is 108 inches wide, what is the width of the full-sized house that it's modeled after? in inches and feet.

Write a description of each inequality. 1. -5a + 3 > 1 2. 27 - 2b < -6 (this < has a _ under it) 3. 1/2 (c + 1) > 5 (this > has a _ under it)