For an art project, Corinne and Amelia want to combine their colored pens and distribute them equally among 12 first graders. If Corinne has 84 colored pens and Amelia has 72 colored pens, how many pens does each first grader get?

10 pens

Step-by-step explanation:

C=84 + A=72 equals 120 pens

120 pens divided by 12 first graders = 10 pens per first grader

Label the given points as follows:
A (0, 5)
B (2, 2)
C (3, 1)
D (4, -1)

The straight line has a constant slope. Therefore it should have the same value when any two of the four points are used to calculate the slope.

Try A and B:
Slope = (2 - 5)/(2 - 0) = -3/2

Try A and C:
Slope = (1 - 5)/(3 - 0) = -4/3

Try A and D.
Slope = (-1 - 5)/(4 - 0) = -3/2

Try B and D.
Slope = (-1 - 2)/(4 - 2) = -3/2

Clearly, C does not lie on the straight line.

 The point that the graph does not pass through is (3,1).