Решение
1) 36х² – 25 = 0
36x² = 25
x² = 25/36
x₁ = - √(25/36)
x₁ = - 5/6
x₂ = √(25/36)
x₂ = 5/6
2) 4х² = 16х
4x² - 16x = 0
4x(x - 4) = 0
x₁ = 0
x - 4 = 0
x₂ = 4
3) (х – 3)² – 2(х – 3) – 15 = 0
Пусть (x - 3) = y, тогда
y² - 2y - 15 = 0
по теореме Виета
y₁ = - 3
y₂ = 5
x - 3 = - 3
x₁ = 0
x - 3 = 5
x₂ = 8