Question

(6х - 10)(6х - 8,5) = (3х - 5)²

Answer 1

36х² - 51х - 60х + 85 = 9х² - 30х + 25
27х² - 81х + 60 = 0
9х² - 27х + 20 = 0
D = 729 - 720 = 9
x₁ = (27-3)/18 = 24/18 = 4/3 = 1 1/3
х₂ = (27+3)/18 = 30/18 = 5/3 = 1 2/3

Answer 2

(6x - 10)(6x - 8,5) = (3x - 5)²
36x² - 51x - 60x + 85 = 9x² - 30x + 25
36x² - 111x + 85 - 9x² + 30x - 25 = 0
27x² - 81x + 60 = 0
9x² - 27x + 20 = 0
D = 729 - 720 = 9
X1,2 = (27 + - 3)/18
X1 = (1)2/3
X2 = (1)1/3