b3=b1*q^2 b6=b1*q^5 b6/b3=b1q^5/b1q^2=q^3=-192/-3=64 q^3=64=4^3 => q=4
b3=b1*q^2=b1*16 -3=16b1 b1=-3/16
2)3х^2-12=0 , 3х^2=12 , х^2=4 , х=-2,х=2
4)(5+y)^+y(y-7)=25+15y+y^2+y^2-7y=2y^2+8y+25
5)(2a-b)(2a+b)+b^2=4a^2-2ab+2ab-b^2+b^2=4a^2
6)(a-c)(a+c)-(a-2c)^2=a^-ac+ac-c^2-a^2+4ac-4c^2=4ac-5c^2
7)(x+3)^2-(x-3)^2=x^2+6x+9-x^2+6x-9=12x