Worked examples
Two examples
Example 1
Factor: x2 − 49
- Both terms are perfect squares, x and 7 squared, with a minus between.
- (first + last)(first − last).
Answer: (x + 7)(x − 7)
Example 2
Factor: 4x2 − 25
- 4x2 is (2x) squared, and 25 is 5 squared.
Answer: (2x + 5)(2x − 5)
Where this is taught: Quiz 39: Polynomials and Factoring, “Factoring a difference of squares”
The drill
Ten problems
How many:
Type your answer as a product, like (x + 2)(x - 3). Then press Check my answers at the bottom.Write each answer on the line. The answer key, with the reasoning, is on the last page.