..........................................................................
14-2-3х+х^2=х^2+4х-9
12-3х+х^2-х^2-4х+9=0
21-7х=0
-7х+21=0
-7х=-21
х=(-21)/(-7)
х=3
..........................................................................
14-2-3х+х^2=х^2+4х-9
12-3х+х^2-х^2-4х+9=0
21-7х=0
-7х+21=0
-7х=-21
х=(-21)/(-7)
х=3