X2 - 4X - 5 = 0 easy factor, what two factors of - 5 add up to - 4 (X + 1)(X - 5) X = - 1 ------------- X = 5 --------------
3x2 - 4x - 5 does not have rational factors. Its roots are x = [4 +/- sqrt(76)]/6 ie -0.7863 and 2.11963 (approx). So the factors are (x + 0.7863) and (x - 2.11963)
(4x + 5)(x - 3)
To factor 4x^2 - 21x + 5, we look for two binomials in the form (Ax + B)(Cx + D) that multiply to give 4x^2 - 21x + 5. We can determine the values of A, B, C, and D by examining the factors of 4 and 5. The factored form is then (4x - 1)(x - 5).
(2x - 1)(6x + 5)
(4x-5)(4x+5)
Find factors of -5 that can be added to make -4, in this case -5 and 1, so: (x - 5)(x + 1) = x2 - 4x - 5
8x^2 + 6x - 5 = 8x^2 + 10x - 4x - 5 = 2x * (4x + 5) - (4x + 5) = (2x -1) * (4x + 5)
X2 - 4X - 5 = 0 easy factor, what two factors of - 5 add up to - 4 (X + 1)(X - 5) X = - 1 ------------- X = 5 --------------
3x2 - 4x - 5 does not have rational factors. Its roots are x = [4 +/- sqrt(76)]/6 ie -0.7863 and 2.11963 (approx). So the factors are (x + 0.7863) and (x - 2.11963)
(4x + 5)(x - 3)
To factor 4x^2 - 21x + 5, we look for two binomials in the form (Ax + B)(Cx + D) that multiply to give 4x^2 - 21x + 5. We can determine the values of A, B, C, and D by examining the factors of 4 and 5. The factored form is then (4x - 1)(x - 5).
5x^2(4x - 5)(5x + 11)
(2x + 5)(2x + 5)
(2x - 1)(6x + 5)
(3x + 1)(x - 5)
20x2 - 27x -8 20 * -8 is -160, and -32 and 5 add to -27 20x2 - 32x + 5x - 8 4x(5x-8) + 1(5x-8) (4x + 1)(5x-8)