SOLUTION: I have three problems that I cannot understand nor sole that involve graphing and solutions will you please help me? 1. Buildings often include stairways of steps with 8 inch ri

Question 463558: I have three problems that I cannot understand nor sole that involve graphing and solutions will you please help me?
1. Buildings often include stairways of steps with 8 inch risers and 12 inch treads. If one were to lay a board on such a stairway to make a temporary ramp, what would the grade, or slope, of the ramp be? (Round to the nearest hundredth.)
2. The amount of farmland in the United States (in millions of acres) can roughly be estimated by the linear equation A = -3t + 940, where A is the amount of farmland in acres and t is the number of years after 1990. Using this equation, approximately how many acres of farmland were there in 1995? In 2000? In 2010? What is the approximate rate of change for the amount of farmland, in acres, with respect to time, in years?

3. The cost, C, in hundreds of dollars, of a commercial telephone line for a business is given by C = 0.8m + 3, where m is the number of months that the telephone line has been in use. Find the cost of the phone line for 1 month, 2 months, 3 months, and 5 months. Insert a graph of this equation, using either Ian Vogt�s graphing website or MML, below.

Answer by edjones(8007) (Show Source): You can put this solution on YOUR website!
tan^(-1)(8/12)=33.69 degrees
.
Ed
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