What you’ll learn
Interpret graph as solution set.
Key idea
A line represents all satisfying ordered pairs, not just the marked examples.
Marked examples are not the only solutions; two repeated points do not define a graph.
Worked example
Enter the exact value or ordered values in the format requested below.
Read numerical y at x=-2 on straight line L, connecting its marked points; x horizontal, y vertical.
Marked coordinates: L=(-3, 8); L=(-2, 6); L=(-1, 4); L=(0, 2); L=(1, 0); L=(2, -2); L=(3, -4).
- The full straight line L has slope -2 and intercept 2; at x=-2 the output is 6.
- Every point satisfying y=-2x+2 lies on L; any two distinct points define its graph, for example (-2,6);(-1,4).
Answer: 6
Quick Check
Relate the graph used in 'Interpret graph as solution set' to an equation, table, transformation, or verbal description.
Connect straight line L to its equation and full solution set, x horizontal, y vertical.
Marked coordinates: L=(3, 6); L=(2, 4); L=(1, 2); L=(0, 0); L=(-1, -2); L=(-2, -4); L=(-3, -6).