Question

Решить уравнения.
1) х^2 + х – 2 = 0
2) 7х^2 – 6х + 2 = 0
3) 9 х^2 + 12х + 4 = 0
4) 2 х^2 – 7х – 4 = 0
5) 1 – 18р + 81р^2 = 0 ( x^2- во второй степени)

Answer 1

решение смотри на фотографии

Answer 2

1) х² + х – 2 = 0
x₁ = -1
x₂ = 2

2) 7х² – 6х + 2 = 0
D = 36 - 4*7*2 = - 20 < 0 нет решений

3) 9х² + 12х + 4 = 0
D = 144 - 4*9*4 = 0
x₁ = x₂ =- 12/18 = - 2/3

4) 2х² – 7х – 4 = 0
D = 49 + 4*2*4 = 81
x₁ = (7 - 9)/4
x₁ = - 1/2
x₂ = (7 + 9)/4
x₂ = 4

5) 1 – 18р + 81р^2 = 0 ( x^2- во второй степени)
81p² - 18p + 1 = 0
D = 324 - 4*81*1 = 0
p₁ = p₂ = 18/2*81
p₁ = p₂ = 1/9