14)2х/(х+4)+27/(х+4)(2х-1)=6/(2х-1) -1
х≠-4 х≠1/2
4х²-2х+27-6х-24+2х²+7х-4=0
6х²-х-1=0
х²-1/6х-1/6=0
х1+х2=1/6 1
15)(2х-6)/(3х-2)(2х+1)+(х-1)/(4х-3)(3х-2)=20х/(4х-3)(2х+1)
х≠2/3 х≠-1/2 х≠3/4
(4х-3)(2х-6)+(х-1)(2х+1)-20х(3х-2)=0
8х²-24х-6х+18+2х²+х-2х-1-60х²+40х=0
-50х²+9х+17=0
х²-9/50-17/50=0
х1+х2=9/50 1
16)х²+1/х² -(5х²+5)/х-4=0
(х²+1/х²+2)-2 -5(х+1/х)-4=0
(х+1/х)²-5(х+1/х)-6=0
х+1/х=а
а²-5а-6=0
а1+а2=5 и а1*а2=-6
а1=-1⇒х+1/х=-1⇒х≠0 и х²+х+1=0⇒решения нет,т.к.D<0<br>а2=6⇒х+1/х=6⇒х≠0 и х²-6х+1=0⇒х1+х2=6 3