5х+6+(х-3)=(5+х)-4
7х=-2
Х=-две седьмых
K-y)^2=2k-2y
(k+7)^2=2k+14
(2k-5)^2=4k-25
(4k+3y)^2=16k+9y
(k2-5y)^2=4k-25y
<span>2.
</span>(*+*)^2=36m^2+*+49n^2
<span>(6m+7n)^2=36m^2+2*6m*7n+49n^2=36m^2+84mn+49n^2</span>
По теореме Виета
х1+х2 = -b и х1*х2 = с, при этом а= 1
b= - (x1+x2) = -(1-2√3+1+2√3) = -2
c= x1*x2 = (1-2√3)*(1+2√3) = 1-7 = -6
значит уравнение:
х^2 -2x-6 = 0