2x²-7x+5 = 0
D = b²-4ac = 49-40 = 9, D>0(значит 2 корня)
x1 = (-b+√D):2a = (7+3):4 = 2,5
x2 = (-b+√D):2a = (7-3):4 = 1
x²-12x+11 = 0
D = b²-4ac = 144-44 = 100, D>0(значит 2 корня)
x1 = (-b+√D):2a = (12+10):2 = 11
x2 = (-b+√D):2a = (12-10):2 = 1
2x²-7x+5 = 0
D = b²-4ac = 49-40 = 9, D>0(значит 2 корня)
x1 = (-b+√D):2a = (7+3):4 = 2,5
x2 = (-b+√D):2a = (7-3):4 = 1
x²-12x+11 = 0
D = b²-4ac = 144-44 = 100, D>0(значит 2 корня)
x1 = (-b+√D):2a = (12+10):2 = 11
x2 = (-b+√D):2a = (12-10):2 = 1