I can use grouping to factor polynomials with four terms.
Factoring Chart This chart will help you to determine which method of factoring to use. Type Number of Terms 1. GCF 2 or more 2. Grouping 4
1. Factor 12ac + 21ad + 8bc + 14bd Do you have a GCF for all 4 terms? No Group the first 2 terms and the last 2 terms. (12ac + 21ad) + (8bc + 14bd) Find the GCF of each group. 3a (4c + 7d) + 2b(4c + 7d) The parentheses are the same! (3a + 2b)(4c + 7d)
2. Factor rx + 2ry + kx + 2ky Check for a GCF: None You have 4 terms - try factoring by grouping. (rx + 2ry) + (kx + 2ky) Find the GCF of each group. r(x + 2y) + k(x + 2y) The parentheses are the same! (r + k)(x + 2y)
3. Factor 2x2 - 3xz - 2xy + 3yz Check for a GCF: None Factor by grouping. Keep a + between the groups. (2x2 - 3xz) + (- 2xy + 3yz) Find the GCF of each group. x(2x – 3z) + y(- 2x + 3z) The signs are opposite in the parentheses! Keep-change-change! x(2x - 3x) - y(2x - 3z) (x - y)(2x - 3z)
4. Factor 16k3 - 4k2p2 - 28kp + 7p3 Check for a GCF: None Factor by grouping. Keep a + between the groups. (16k3 - 4k2p2 ) + (-28kp + 7p3) Find the GCF of each group. 4k2(4k - p2) + 7p(-4k + p2) The signs are opposite in the parentheses! Keep-change-change! 4k2(4k - p2) - 7p(4k - p2) (4k2 - 7p)(4k - p2)
Zero Product Property If a • b = 0 then a=0, b=0, or both a and b equal 0.
1. Solve (x + 3)(x - 5) = 0 Using the Zero Product Property, you know that either x + 3 = 0 or x - 5 = 0 Solve each equation. x = -3 or x = 5 {-3, 5}
3t + 5 = 0 or t - 3 = 0 3t = -5 or t = 3 t = -5/3 or t = 3 {-5/3, 3} 3. Solve (3t + 5)(t - 3) = 0 3t + 5 = 0 or t - 3 = 0 3t = -5 or t = 3 t = -5/3 or t = 3 {-5/3, 3}
4. Solve x2 - 11x = 0 GCF = x x(x - 11) = 0 x = 0 or x - 11 = 0 {0, 11} Set = 0 Factor Split/Solve Check