x^2+x -56=0D = 225x1=-8x2 =7x^2 -x - 2 =0D = 9x1= -1x2 =2x^2 -4x - 5 =0D= 36x1=-1x2 =5x^2 + 8x + 12 = 0D=16x1=-6x2 =-2x^2 +4x + 7 = 0D= -12 (корней нет)
x^2+x -56=0
D = 225
x1=-8
x2 =7
x^2 -x - 2 =0
D = 9
x1= -1
x2 =2
x^2 -4x - 5 =0
D= 36
x1=-1
x2 =5
x^2 + 8x + 12 = 0
D=16
x1=-6
x2 =-2
x^2 +4x + 7 = 0
D= -12 (корней нет)