Решите уравнение : а) (x-1)²+(x+1)²=(x+2)²-2x+2; b) (2x-3) (2x+3)-1=5x+(x-2)²;
▪а) (x-1)²+(x+1)²=(x+2)²-2x+2; x² - 2х + 1 + x² + 2х + 1 = x² + 4х + 4 - 2х + 2 2x² + 2 - x² - 2х - 6 = 0 x² - 2х - 4 = 0 D= b² - 4ac = 4 - 4 × (-4) = 4 + 16 = 20 ▪b) (2x-3) (2x+3)-1=5x+(x-2)² 4x² - 9 - 1 = 5x + x² - 4x + 4 4x² - x² - 10 - x - 4 = 0 3x² - x - 14 = 0 D= b² - 4ac = 1 - 4 × 3 × (-14) = 1 + 168 = 169