solve this quadratic equations..
Answers
Step-by-step explanation:
(a) x^2 + 6x + 5 = 0
= x^2 + 6x + 5 = 0
= x^2- 5x - x+ 5 = 0
= x (x - 5) - 1 ( x - 5) = 0
= (x - 5 ) (x - 1) = 0
(b) 8x^2 - 22x - 21 = 0
= 4x (2X - 7) + 3 (2x - 7) = 0
= (4x + 3) (2x - 7) = 0
= 4x - 13 = 0 or 2x - 7 = 0
= 4x = -3 or 2x = 7
= x = - 3/4
= 4x = 7/2
(c) 9x^2 - 3x -2 = 0
= 9x^2 - 6x + 3x - 2 = 0
= 3x (3x - 2) + 1 (3x - 2) = 0
= (3x - 2) (3x + 1) = 0
= 3x - 2 = 0 or 3x + 1 = 0
= 3x = 2 and 3x = - 1
= x = 2/3 and x = - 1/3
(d) x^2 + 2√2 - 6 = 0
= x^2 +2 √2x - √2x - 6 = 0
= x(x + 3√2) - √2(x+3√2)=0
= (x+3√2) (x-√2) = 0
= x+3√2 = 0 or x-√2 = 0
= x = -3√2 or x =√2
(e)√3^2 + 10x + 7√3 = 0
= 3x^2 + 3 x + 7x + 7√3 = 0
= √3 x (x+√3) + 7(x +√3) = 0
= (x+√3) (√3+7) = 0
= √3x + 7 = 0 or x + √3 = 0
= x = - √3 or x = - 7/√3