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Unit 6: lesson 8.4 SWBAT solve polynomial equations in factored form & factor the GCF. Section 8.4 “Solve Polynomial Equations in Factored Form”. Zero-Product Property. If ab = 0, then a = 0 or b = 0.
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Unit 6: lesson 8.4 SWBAT solve polynomial equations in factored form & factor the GCF.
Section 8.4 “Solve Polynomial Equations in Factored Form” Zero-Product Property If ab = 0, then a = 0 or b = 0. The zero-product property is used to solve an equation when one side of the equation is ZERO and the other side is the product of polynomial factors. (x – 4)(x + 2) = 0 The solutions of such an equation are called ROOTS. x + 2 = 0 x – 4 = 0 x = -2 x = 4
Example 1A: Use the Zero Product Property Use the Zero Product Property to solve the equation. Check your answer. (x – 7)(x + 2) = 0 Use the Zero Product Property. x – 7 = 0 or x + 2 = 0 Solve each equation. x = 7 or x = –2 The solutions are 7 and –2.
Example 1B: Use the Zero Product Property Use the Zero Product Property to solve each equation. Check your answer. (x – 2)(x) = 0 (x)(x – 2) = 0 Use the Zero Product Property. x= 0 or x – 2 = 0 Solve the second equation. x = 2 The solutions are 0 and 2.
Use the Zero Product Property to solve the equation. Check your answer. (x + 4)(x – 3) = 0 Use the Zero Product Property. x + 4 = 0 or x – 3 = 0 x = –4 or x = 3 Solve each equation. The solutions are –4 and 3.
Solve the equations (x – 5)(x + 1) = 0 (2x – 3)(4x + 1) = 0
Using the Zero Product Property Solve the equation (x – 1)(x + 7) = 0
You try: Solve the equation (z – 6)(z + 6) = 0.
Try this one: Solve the equation (x – 4)2 = 0
a. The GCF of 12 and 42 is 6. The variables xand yhave no common factor. So, the greatest common monomial factor of the terms is 6. ANSWER 12x + 42y = 6(2x + 7y) Factor out the greatest common monomial factor. a.12x + 42y SOLUTION
b. The GCF of 4 and 24 is 4. The GCF of x4 and x3 is x3. So, the greatest common monomial factor of the terms is 4x3. ANSWER 4x4+ 24x3 = 4x3(x + 6) Factor out the greatest common monomial factor. b. 4x4+ 24x3 SOLUTION
ANSWER 14m+ 35n = 7(2m + 5n) GUIDED PRACTICE 2. Factor out the greatest common monomial factor from 14m + 35n.
ANSWER The solutions of the equation are 0 and – 4. EXAMPLE 3 Solve2x2+ 8x = 0. 2x2+ 8x = 0 Write original equation. 2x(x + 4) = 0 Factor left side. or x + 4 = 0 2x= 0 Zero-product property or x = 0 x =– 4 Solve for x.
5 5 2 2 n = ANSWER . The solutions of the equation are 0 and Solve 6n2 = 15n. 6n2– 15n = 0 Subtract 15nfrom each side. 3n(2n – 5) =0 Factor left side. or 2n – 5= 0 3n= 0 Zero-product property or n = 0 Solve for n.
1 1 2 2 ANSWER ANSWER ANSWER 0 and – 5 0 and 3 . 0 and GUIDED PRACTICE Solve the equation. 3. a2+ 5a = 0 5. 4x2 = 2x. 4. 3s2– 9s = 0