Cogito
Algebra 1 · Chapter 2 · Lesson 1
Solving Inequalities
One rule is different, and it matters.
10 problems · about 19 minutes · A-REI.B.3
Figure — use these to answer the problems
Warm-Up Review
From earlier lessons. Loosen up before the new work.
2 problemsFrom “Absolute Value Equations”
|x − 4| = 3. What is the larger solution?
AnswerFrom “No Solution, or Every Solution”
8x + 2 = 8x + 11. How many solutions?
Answer
Warm Up
Straightforward practice. Get the method working first.
4 problemsSolve −2x ≥ 14. Boundary value?
AnswerWhy does the sign reverse with a negative?
- Multiplying by a negative reverses the order on the line.
- Because that is the rule.
Solve 2x − 3 > 7. Boundary value?
AnswerSolve −3x < 12. Boundary value?
Answer
Build It Up
The same ideas with more to keep track of.
2 problemsSolve 5x + 2 ≤ 27. Boundary value?
AnswerDoes dividing by a positive reverse the sign?
- No. Only a negative does.
- Yes.
Stretch Yourself
Mixed problems. Work out what kind of question it is before you start.
2 problemsThe Range
Solve 3x + 4 < 19. What is the boundary value of x?
AnswerThe Flip
Solve −4x > 20. What is the boundary value of x?
Answer