(х+3)³ - (х+3)² * х + 3(х+3) = 0,
(х+3)((х+3)² - х(х+3) + 3) = 0,
(х+3)(х²+6х+9 - х²-3х + 3) = 0,
(х+3)(3х+12) = 0,
х+3 = 0,
х1 = -3,
3х+12 = 0,
3х = -12,
х2 = -4
<span>(3x – 7y)^2=9x^2-42xy+49y^2
Квадрат разности</span>
4a*(-3b)=-12ab
----------------------
D=a2-a1=a3-a2=a4-a3=.......
d=9-3=15-9=--------
d=6
=====