Error Analysis

The value of x is going up by 5, so the slope should be 2 and not 10/1. By plugging in the points, the final equation should be solved. With this answer, y is not equal to 9+10x in the t-chart.

In order for a point to be the solution to a system, it has to solve both equations. So point (1,-2) solves the first equation, but not the second equation.

For problem #22 the shading is right, but the line should be dotted, not soild. For problem #23 the solid line is right, but the shading should be above it, not below it.

For problem #20 the shading is correct, but the line should be dotted not solid. For problem #21 the sloid line is right, but the shading should be below it not above it.