Graphs of Linear equations
Applications of Linear Equations
Questions that arise in the real world are usually expressed in words, rather than in mathematical symbols. Problems in which a question is asked and pertinent information is supplied in the form of words are called “word problems” or “story problems”.
For working these problems, we recommended the following systematic procedure:
Step 1. Begin by reading the problem carefully, several times if necessary, until you understand it well. Draw a diagram whenever possible. Look for the question or questions you are to answer.
Step 2. List all of the unknown numerical quantities involved in the problem. It may be useful to arrange these quantities in a table or chart along with related know quantities. Select one of the unknown quantities on your list, one that seems to play a prominent role in the problem, and call it x. (Of course, any other letter will do as well.)
"Pump-U-Up" gym charges a $100 enrollment fee, plus $35 per month to be a member. Write an equation that represents the cost as a function of the number of months enrolled. Make a table of values and draw the graph.
The equation that represents the cost as a function of the months enrolled is:
The table of values is:
The graph is:
A hot air balloon is 200 feet up and descending at a rate of 10 feet every 3 minutes.
The graph is:
c) 100 ft