a) x - 2 = 0
x = 2
e) x² = 0
x = √0 = 0
i) x² + x = 0
x(x + 1) = 0
x₁ = 0 x + 1 = 0
x₂ = -1
m) x² - 2x + 1 = 0
D = 2² - 4 * 1 * 1 = 0 = 0
x = -b/2a = 2/(2 * 1) = 1
r) √x = 3
х = 3² = 9
b) 3x + 12 = 12
3x = 0
x = 0
f) x² = 9
x₁ = -√9 = -3
x₂ = √9 = 3
j) 5x² + 10x = 0
5x(x + 2) = 0
5x = 0 x + 2 = 0
x₁ = 0 x₂ = -2
n) x² - 2x - 3 = 0
По теореме Виета х₁ = -1
х₂ = 3
s) √x = -3
x = (-3)² = 9
c) -x + 9 = -1
-x = -10
x = 10
g) x² = -2
корней нет, т.к. нет такого числа, при возведение которого во вторую степень, получалось бы отрицательное число
k) -7x² + x = 0
x - 7x² = 0
x(1 - 7x) = 0
x₁ = 0 1 - 7x = 0
x₂ = -1 : (-7) =
o) x² - 2x + 3 = 0
D = (-2)² - 4 * 1 * 3 = -8 < 0
Корней нет.
t)
x - 1 ≠0
x≠1
x² + 2x = 0
x(x + 2) = 0
x₁ = 0 x + 2 = 0
x₂ = -2