1)х²-9х+14=0 3)4х²-20х\=21=0
(х²-4х+4)-5х+10=0 4х²-12х+9-8х+12=0
(х-2)²-5(х-2)=0 (2х-3)²-4(2х-3)=0
(х-2)(х-2-5)=0 (2х-3)(2х-3-4)=0
(х-2)(х-7)=0 (2х-3)(2х-7)=0
х=2 х=7 х=3\2 х=7\2
4)9х²-12-5=0
9х²-30х+25+18х-30=0
(3х-5)²+6(3х-5)=0
(3х-5)(3х-5+6)=0
(3х-5)(3х+1)
х=5\3 х=-1\3