Suppose you are saving money for a new cell phone. At week 0 you have $20 and at week 10 you have $100. If y represents the amount of money you have saved and x represents the number of weeks, find and interpret the slope of the linear equation. A. 1/8 ; $8 is put away each week. B. 10; $10 is put away each week. C. 8; $8 is put away each week. D. 1/10; $10 is put away each week
If we plot the given values in the Cartesian plane, the points to which the line would pass are (0, 20) and (10, 100). Thus, the slope m is,
m = (y2 - y1) / (x2 - x1)
Substituting,
m = (100 - 20) / (10 - 0) = 8
Thus, I saved 8 pesos per week. The answer to the question is letter C.
you have 2 points (0,20) and (10,100)
now find the slope using change in y divided by change in x
m=(100-20)/(10-0)
m=80/10
m=8 is the slope