@ @YU@ @pý†bɾa@ @
:
α + 1 + β + 1 = (α + β) + α + β = 6 + 6 = 48
βα αβ 7 7
:
α + 1 β + 1 = αβ + 1 + 2 = 7 + 1 + 2 = 64
β α αβ 7 7
:
7x2 − 48x + 64 = 0
. 12 .
()
20
. 12 − x . x
.A
A = 1 x(12 − x)
2
1 x(12 − x) = 20
2
x(12 − x) = 40
12x − x 2 − 40 = 0
x 2 − 12x + 40 = 0