Aspring has an original length l inches. when a weight of x pounds is suspended from the spring, its new length y is given by the formula y = l +
x
k
, where k is a constant, measured in pounds per inch.
solve the formula for x. show the steps in your work.
the value of k for a certain spring is 2.5. the length of the spring is found to be double its original length when a 10 pound weight is suspended from it. write the equation for the original length of the spring and solve it. show the steps in your work.

Mary used 1/7 of a spool of ribbon to complete 4 projects. she used the same amount of ribbon on each project. how much ribbon did she use on each project?

The position of a moving particle is given by the position function: f(t)=-9t-t^2-0.2t^3+0.1t^4 0 a. at what time does the particle reverse direction? b. when is the displacement positive? (round one decimal place and answer in interval notation) c. when is the displacement negative? (round one decimal place and answer in interval notation) d. when is the particle’s acceleration positive? (round one decimal place and answer in interval notation) e. when is the particle’s acceleration negative? (round one decimal place and answer in interval notation)

Marquise has 200 meters of fencing to build a rectangular garden. the garden's area (in square meters) as a function of the garden's width w w (in meters) is modeled by: a ( w ) = − w 2 + 1 0 0 w a(w)=−w 2 +100w what side width will produce the maximum garden area? meters