A highlight of student work this week was using the Slope-Intercept make equations, find patterns in data, and create scatter plot graphs. It was also neat to see how students began to think of solving a system of equations using graphs of the equations:
y=.49x +10
y=.99x
Students found that the graphing calculator tool, meta-calculator.com, produced quick and accurate results.
The solution to the 2 equations above is the point where the lines intersect. This point is at approximately (20,20). So, how does this graph help answer last week's Music Download word problem?
Our definition for the variables... x= the number of songs, and the variable y= the cost of the songs.
We discovered that ...When 20 songs are purchased the price of the 2 plans happens to be the same. (around $20).
Therefore...When more than 20 songs are purchased the first plan is a better deal, when less than 20 songs are purchased the 2nd plan is cheaper.
Use the graphing calculator application to solve this problem: What solution do you find for the system of equations?
y= -3x+2
y= 2x-3
How would you check to make sure this solution is correct?
Find more interactive practice problems with answers at http://regentsprep.org/REgents/math/ALGEBRA/AE3/PracGr.htm
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