Problem 27)
Refer to the diagram that says "problem 27".
This is the graph of y = 5x where x is the time in years, and y is the amount of simple interest in the account.
This equation comes from the simple interest formula below
i = P*r*t
i = 100*0.05*x
i = 5x
y = 5x
Note: The graph is a straight line through (0,0) and (1,5)
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Problem 28)
The abscissa is the x coordinate. For a point like (-3, -7), the abscissa is -3.
The ordinate is the y coordinate. For that point mentioned earlier, the ordinate is -7.
The graph of points is shown below in the figure labeled "problem 28".
When graphing any point, we always start at the origin (0,0) where the x and y axis meet up. Then for a point like (-3,-7) we move 3 units to the left on the x axis and 7 units down on the y axis to arrive at point A. The other points are plotted in a similar fashion. The labels A,B,C,D are optional. They were added to help keep track of the points.