Worked examples
Two examples
Example 1
Two lines on a grid cross at the point 2 to the right and 1 down from the origin. What is the solution of the system?
- The solution is the point that is on both lines: where they cross.
Answer: (2, −1)
Example 2
One line crosses the other exactly on the y-axis, 3 above the origin. What is the solution?
- On the y-axis, x = 0.
Answer: (0, 3)
Where this is taught: Quiz 42: Lines, Slope, and Systems, “Two lines at once: a system”
The drill
Ten problems
This drill also has challenge problems. They use the same skill, set up the way the GED test sometimes sets up a problem, so that it looks new at first.
How many:
Type each answer as a point, like (3, -2). Then press Check my answers at the bottom.Write each answer as a point, like (3, −2). The answer key, with the reasoning, is on the last page.