13-4

1. Subtracting Polynomials 13-4 Warm Up Problem of the Day Lesson Presentation Pre-Algebra

2. Subtracting Polynomials 13-4 Warm Up Write the opposite of each integer. 1.10 Subtract. 3. 19 – (–12) Add. 5. (3x2 + 7) + (x2– 3x) 6. (2m2 – 3m) + (–5m2 + 2) –10 2. –7 7 31 4. –16 – 21 –37 4x2– 3x + 7 –3m2– 3m + 2 Pre-Algebra

3. Subtracting Polynomials 13-4 Problem of the Day Tara has 4 pairs of shorts, 3 tops, and 2 pairs of sandals. If she wants to wear a completely different outfit than she wore yesterday, how many combinations does she have to choose from? 6 Pre-Algebra

4. Subtracting Polynomials 13-4 Learn to subtract polynomials. Pre-Algebra

5. Subtracting Polynomials 13-4 Subtraction is the opposite of addition. To subtract a polynomial, you need to find its opposite. Pre-Algebra

6. Subtracting Polynomials 13-4 Additional Example 1A & 1B: Finding the Opposite of a Polynomial Find the opposite of each polynomial. A. 8x3y4z2 –(8x3y4z2) The opposite of a is –a. –8x3y4z2 B. –3x4 + 8x2 –(–3x4 + 8x2) Distribute the sign. 3x4– 8x2 Pre-Algebra

7. Subtracting Polynomials 13-4 Additional Example 1C: Finding the Opposite of a Polynomial Find the opposite of the polynomial. A. 9a6b4 + a4b2– 1 –(9a6b4 + a4b2– 1) Distribute the sign. –9a6b4 –a4b2 + 1 Pre-Algebra

8. Subtracting Polynomials 13-4 Insert Lesson Title Here Try This: Example 1A & 1B Find the opposite of each polynomial. A. 4d2e3f3 –(4d2e3f3) –4d2e3f3 The opposite of a is –a. B. –4a2 + 4a4 –(–4a2 + 4a4) Distribute the sign. 4a2– 4a4 Pre-Algebra

9. Subtracting Polynomials 13-4 Insert Lesson Title Here Try This: Example 1C Find the opposite of the polynomial. A. 9a6b4 + a4b2– 1 –(9a6b4 + a4b2– 1) –9a6b4 –a4b2 + 1 Distribute the sign. Pre-Algebra

10. Subtracting Polynomials 13-4 To subtract a polynomial, add its opposite. Pre-Algebra

11. Subtracting Polynomials 13-4 Additional Example 2A: Subtracting Polynomials Horizontally Subtract. A. (5x2 + 2x– 3) – (3x2 + 8x– 4) Add the opposite. = (5x2 + 2x– 3) + (–3x2– 8x+ 4) Associative property. = 5x2 + 2x– 3 – 3x2– 8x + 4 = 2x2– 6x + 1 Combine like terms. Pre-Algebra

12. Subtracting Polynomials 13-4 Additional Example 2B: Subtracting Polynomials Horizontally Subtract. B. (b2 + 4b – 1) – (7b2–b– 1) Add the opposite. = (b2 + 4b – 1) + (–7b2+b+ 1) Associative property. = b2 + 4b – 1 –7b2 + b + 1 = –6b2 + 5b Combine like terms. Pre-Algebra

13. Subtracting Polynomials 13-4 Insert Lesson Title Here Try This: Example 2A Subtract. A. (2y3 + 3y + 5) – (4y3 + 3y + 5) Add the opposite. = (2y3 + 3y + 5) + (–4y3– 3y – 5) Associative property. = 2y3 + 3y + 5 – 4y3– 3y– 5 = –2y3 Combine like terms. Pre-Algebra

14. Subtracting Polynomials 13-4 Insert Lesson Title Here Try This: Example 2B Subtract. B. (c3 + 2c2+ 3) – (4c3–c2– 1) = (c3 + 2c2+ 3) + (–4c3+c2+ 1) Add the opposite. = c3 + 2c2+ 3 – 4c3 + c2 + 1 Associative property. = –3c3 + 3c2 + 4 Combine like terms. Pre-Algebra

15. Subtracting Polynomials 13-4 You can also subtract polynomials in a vertical format. Write the second polynomial below the first one, lining up the decimal points. Pre-Algebra

16. Subtracting Polynomials 13-4 Additional Example 3A: Subtracting Polynomials Vertically Subtract. A. (2n2– 4n + 9) – (6n2– 7n + 5) (2n2– 4n + 9) 2n2– 4n + 9 – (6n2 – 7n + 5) +–6n2 + 7n –5 Add the opposite. –4n2 + 3n + 4 Pre-Algebra

17. Subtracting Polynomials 13-4 Additional Example 3B: Subtracting Polynomials Vertically Subtract. B. (10x2 + 2x –7) – (x2 + 5x + 1) (10x2 + 2x –7) 10x2 + 2x –7 Add the opposite. – (x2 + 5x + 1) + –x2– 5x– 1 9x2– 3x– 8 Pre-Algebra

18. Subtracting Polynomials 13-4 Additional Example 3C: Subtracting Polynomials Vertically Subtract. C. (6a4– 3a2–8) – (–2a4 + 7) (6a4– 3a2–8) 6a4– 3a2–8 – (–2a4 + 7) + 2a4– 7 Add the opposite. 8a4 – 3a2– 15 Pre-Algebra

19. Subtracting Polynomials 13-4 Insert Lesson Title Here Try This: Example 3A Subtract. A. (4r3 + 4r + 6) – (6r3 + 3r + 3) (4r3 + 4r + 6) 4r3 + 4r + 6 Add the opposite. – (6r3 + 3r + 3) + –6r3– 3r –3 –2r3 + r + 3 Pre-Algebra

20. Subtracting Polynomials 13-4 Insert Lesson Title Here Try This: Example 3B Subtract. B. (13y2– 2x + 5) – (y2 + 5x– 9) (13y2– 2x + 5) 13y2– 2x + 5 – (y2 + 5x– 9) + –y2– 5x + 9 Add the opposite. 12x2– 7x + 14 Pre-Algebra

21. Subtracting Polynomials 13-4 Insert Lesson Title Here Try This: Example 3C Subtract. C. (5x2 + 2x + 5) – (–3x2– 7x) (5x2 + 2x + 5) 5x2 + 2x + 5 +3x2 + 7x – (–3x2– 7x) Add the opposite. 8x2 + 9x+ 5 Pre-Algebra

22. Subtracting Polynomials 13-4 Additional Example 4: Business Application Suppose the cost in dollars of producing x bookcases is given by the polynomial 250 + 128x, and the revenue generated from sales is given by the polynomial 216x– 75. Find a polynomial expression for the profit from producing and selling x bookcases, and evaluate the expression for x = 95. 216x – 75 – (250 + 128x) revenue – cost Add the opposite. 216x – 75 + (–250 – 128x) Associative Property 216x – 75 – 250 – 128x Combine like terms. 88x – 325 Pre-Algebra

23. Subtracting Polynomials 13-4 Additional Example 4 Continued The profit is given by the polynomial 88x– 325. For x = 95, 88(95) – 325 = 8360 – 325 = 8035 The profit is $8035. Pre-Algebra

24. Subtracting Polynomials 13-4 Insert Lesson Title Here Try This: Example 4 Suppose the cost in dollars of producing x baseball bats is given by the polynomial 6 + 12x, and the revenue generated from sales is given by the polynomial 35x– 5. Find a polynomial expression for the profit from producing and selling x baseball bats, and evaluate the expression for x = 50. 35x – 5 – (6 + 12x) revenue – cost Add the opposite. 35x – 5 + (–6 – 12x) Associative Property 35x – 5 – 6 – 12x 23x – 11 Combine like terms. Pre-Algebra

25. Subtracting Polynomials 13-4 Insert Lesson Title Here Try This: Example 4 Continued The profit is given by the polynomial 23x– 11. For x = 50, 23(50) – 11 = 1150 – 11 = 1139 The profit is $1139. Pre-Algebra

26. Subtracting Polynomials 13-4 Insert Lesson Title Here Lesson Quiz Find the opposite of each polynomial. Subtract. 3. (3z2 – 7z + 6) – (2z2 + z– 12) 2.–3m3 + 2m2n 3m3– 2m2n 1. 3a2b2c3 –3a2b2c3 z2– 8z + 18 4.–18h3– (4h3 + h2– 12h + 2) 5. (3b2c + 5bc2– 8b2) – (4b2c + 2bc2–c2) –22h3–h2 + 12h– 2 –b2c + 3bc2– 8b2 + c2 Pre-Algebra