Math 1 · Unit 5 · Lesson 3 · part 3 of 6
Match by elimination: three clues, boundary first
The other direction is the elimination habit from Unit 3, now with two extra clues.
Match by elimination: three clues, boundary first
The other direction is the elimination habit from Unit 3, now with two extra clues. Given an inequality and several graphs, do not plug in points to find the answer. Read what the inequality forces, cross out every graph that breaks a clue, and check the one that is left.
- 1Boundary firstThe slope and the y-intercept of the boundary must match. Cross out every graph whose line is wrong (wrong direction, wrong crossing, wrong steepness).
- 2Then the line styleStrict sign: the survivor must be dashed. Inclusive sign: solid. Cross out the wrong style.
- 3Then the shaded sideWith y alone: greater means above, less means below. Cross out the wrong side. One is left. Plug in a point only to double-check.
Write the answer with the cluesSay what ruled out each wrong graph: that one's boundary crosses at 3 but b is −1; that one is solid but the sign is strict; that one shades above but y is less than. That sentence is the understanding, the same as in Unit 3.