Решите уравнениие 3)16х^2-2х-5=0 4)-7х^2-4х+11=0

3) 16x² - 2x - 5 = 0
D = b² - 4ac = 4 - 4 × 16 × (-5) = 4 + 320 = 324 = 18²
x1 = ( 2 + 18) / 32 = 0,625
x2 = ( 2 - 18) / 32 = - 0,5

4) - 7x² - 4x + 11 = 0
7x² + 4x - 11 = 0
D = b² - 4ac = 16 - 4 × 7 × ( - 11) = 16 + 308 = 324 = 18²
x1 = ( - 4 + 18) / 14 = 1
x2 = ( - 4 - 18) / 14 = - 22/14 = - 11/7 = - 1 целая 4/7