-3ab^2 * 4a^2b^2c * 8a^3b^9c^12 = -96a^6b^13c^13
А 2x^2+6x-x-3=0
2^2+5-3=0
Дмскрименат=25+24=49 √49=7
х1= -5-7/4=-3
х2=-5+7/4=0.5.
1)=3a^2+6a-a2-6a+9= 2a^2-9
2)=8c+4(1-2c+c^2)=8c+4-8c+4c^2=4+4c^2
3)=a^2-8a+16-6a^2+8a=16-5a
4)=x^2+4x-2x-8-2x-2x^2=-x^2-8
5)=d^2+2d-4d-8-d^2+2d-1=-9