Question

ПОМОГИТЕ РЕШИТЬ УРАВНЕНИЯ(8 КЛАСС) 1)х^2+25=0 2)х^2-196=0 3)х^2-196х=0 4)х^2-10х+16=0 5)8х^2-14х+5=0

Answer 1

1) x² + 25 = 0
x² = -25
Нет решений!

2) x² - 196 = 0
x² = 196
x = +- 14

3) x² - 196x = 0
x (x - 196) = 0
x = 0 и x = 196

4) x² - 10x + 16 = 0
D = 100 - 16 * 4 = 100 - 64 = 36
x₁ = 10 + 6 / 2 = 8
x₂ = 4 / 2 = 2

5) 8x² - 14x + 5 = 0
D = 196 - 8 * 5 * 4 = 196 - 160 = 36
x₁ = 14 + 6 / 16 = 20 / 16 = 10 / 8 = 5 / 4 = 1,25
x₂ = 14 - 6 / 16 =  8 / 16 = 0,5

Answer 2

спасибо