Cogito
Algebra 1 · Chapter 7 · Lesson 2
Factoring Quadratic Trinomials
Two numbers that multiply and add correctly.
11 problems · about 24 minutes · A-SSE.A.2, A-SSE.B.3
Figure — use these to answer the problems
8 + 8 + 8 + 8 + 8 = 40
5 × 8 = 40
5 × 8 = (5 × 3) + (5 × 5) = 15 + 25 = 40
Warm Up
Straightforward practice. Get the method working first.
4 problemsMultiply to 18, add to 9. Larger number?
AnswerMultiply to 6, add to 5. Larger number?
AnswerMultiply to 15, add to 8. Larger number?
AnswerMultiply to 9, add to 6. Larger number?
Answer
Build It Up
The same ideas with more to keep track of.
3 problemsMultiply to −12, add to 1. Positive number?
Answerx² + 5x + 6 factors to (x + 2)(x + ?). What is the missing number?
AnswerA positive constant with a positive middle term. Are both numbers positive? 1 for yes, 0 for no.
Answer
Stretch Yourself
Mixed problems. Work out what kind of question it is before you start.
4 problemsMultiply to 20, add to 9. Larger number?
AnswerOrder the steps for factoring x² + bx + c.
Write 1 to 4 in the boxes to put these in order.
- List pairs multiplying to c
- Find the pair adding to b
- Write the two brackets
- Expand to check
The Pair
Two numbers multiply to 12 and add to 7. What is the larger?
AnswerA Negative Constant
Two numbers multiply to −10 and add to 3. What is the positive one?
Answer