x2 - x - 42 = 0D = b2 - 4acD = 1 + 168 = 169 = 13^2
x1,2 = -b ± √D/2ax1 = 1 + 13/2 = 14/2 = 7x2 = 1 - 13/2 = - 12/2 = -6ответ: x1 = 7; x2 = -6
x2 - x - 42 =(x-7)(x+6)
x2 - x - 42 = 0
D = b2 - 4ac
D = 1 + 168 = 169 = 13^2
x1,2 = -b ± √D/2a
x1 = 1 + 13/2 = 14/2 = 7
x2 = 1 - 13/2 = - 12/2 = -6
ответ: x1 = 7; x2 = -6
x2 - x - 42 =(x-7)(x+6)