Question

помогите решить уравнение!!
(2x+1)(x-7) = (3x-1)² - 30

Answer 1

Розв'язок:

(2x+1)(x-7) = (3x-1)²-30

2x²-14x+x-7 = 9x²-6x+1-30

-7x²-7x+22 = 0|(-1)

7x²+7x-22 = 0

D = b²-4ac, де a = 7; b = 7; c = -22

D = 49-4·7·(-22) = 49-28(-22) = 49+616 = 665 > 0.

x1,2 = (-b±√D)/2a

x1,2 = (-7±√665)/14

x1 = (-7-√665)/14

x2 = (-7+√665)/14

Відповідь: x1 = (-7-√665)/14

x2 = (-7+√665)/14