1) ( x - 2)² - ( x - 2)( x + 2) = ( x - 2)( x - 2) - ( x² + 2x - 2x - 4) = x² - 2x - 2x + 4 - -x² - 2x + 2x + 4 = - 4x + 8 = - 4 ( x - 2)
3) 10x² - 250 = 0
D = b² - 4ac
D = 0² - 4 × 10 × ( - 250) = 10000 = 100²
x₁ = 0 + 100 / 2 × 10 = 100/ 20 = 5
x₂ = 0 - 100 / 2 × 10 = - 100 / 20 = - 5
Ответ: положительный корень уравнения x = 5
5) 4 ( x - 3) = x + 3
4x - 12 = x + 3
4x - x = 12 + 3
3x = 15
x = 15 ÷ 3
x = 5
Ответ: x = 5