142k views
0 votes
If Peter has to subtract (x² - 2x - 4) from (x² + 3x + 5), here is his work. Explain what is wrong with Peter's working.

User Beresfordt
by
7.6k points

1 Answer

3 votes

Final answer:

Peter needs to subtract the second polynomial from the first polynomial by changing the signs and combining like terms, resulting in the correct answer: 5x + 9.

Step-by-step explanation:

The student, Peter, is presented with the task of subtracting one polynomial, (x² - 2x - 4), from another, (x² + 3x + 5). To perform the subtraction correctly, Peter needs to subtract each term of the second polynomial from the corresponding term of the first polynomial. The subtraction should be done as follows:

  1. Keep the first polynomial as is: (x² + 3x + 5).
  2. Change the sign of each term of the second polynomial: (-x² + 2x + 4).
  3. Combine like terms: (x² + 3x + 5) - (x² - 2x - 4) becomes x² + 3x + 5 - x² + 2x + 4.
  4. Simplify the expression: (3x + 2x) + (5 + 4), resulting in 5x + 9.

Peter's mistake might be in the signs when performing the subtraction or in incorrectly combining like terms.

User Ranbuch
by
7.6k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.