по теореме Виета
х1+х2=-7/3
х1*х2=-11/3
2x1x2 +-x1-x2=2x1x2 -(x1+x2)=2*(-11/3)-(-7/3)=-22/3+7/3=-15/3=-5
1)3x2=27
x2=9
x1=-3
x2=3
2)3x(x+4)=0
3x=0
x1=0 или x+4=0
x=-4
3)D=82-56=25
x1=-9+5/2×7=-4/14=-2/7
x2=-9-5/2×7=-14/14=-1
17+33+49+65+81+97+113+129+145+161+177=1067
(3a-b)(2b-4a)=3a*2b-b*2b-3a*4a+b*4a=6ab-2b²-12a²+4ab=-12a²-2b²+10ab