Найди корни уравнения (5x - 8)² - 5 · (5x - 8) + 6 = 0.
(5x - 8)² - 5 · (5x - 8) + 6 = 0
25x² - 80x + 64 - 25x + 40 + 6 = 0
25x² - 105x + 110 = 0 | : 5
5x² - 21x + 22 = 0
D = (-21)² - 4 · 5 · 22 = 441 - 440 = 1
x₁,₂ = (21 ± √1)/(2 · 5) = (21 ± 1)/10
x₁ = (21 - 1)/10 = 20/10 = 2
x₂ = (21 + 1)/10 = 22/10
ответ: 22/10, 2.
Найди корни уравнения (5x - 8)² - 5 · (5x - 8) + 6 = 0.
(5x - 8)² - 5 · (5x - 8) + 6 = 0
25x² - 80x + 64 - 25x + 40 + 6 = 0
25x² - 105x + 110 = 0 | : 5
5x² - 21x + 22 = 0
D = (-21)² - 4 · 5 · 22 = 441 - 440 = 1
x₁,₂ = (21 ± √1)/(2 · 5) = (21 ± 1)/10
x₁ = (21 - 1)/10 = 20/10 = 2
x₂ = (21 + 1)/10 = 22/10
ответ: 22/10, 2.