СРОЧНО! разложите на множители а)с^2-16c b)3a^2-16ab+3b^2 c)81a^4-1 d)y^2-x^2-6x-9
а)с^2-16c =с(с-16)
b)3a^2-16ab+3b^2=1/3(3a-8b+b*sqrt(55))(3a-8b-b*sqrt(55))
c)81a^4-1 =(9a^2-1)(9a^2+1)=(3a-1)(3a+1)(9a^2+1)
d)y^2-x^2-6x-9=y^2-(x+3)^2=(y-x-3)(y+x+3)
а) с^2-16c=с*(с-16);
b) 3a^2-16ab+3b^2=1/3*(3a-8b+b*V55)*(3a-8b-b*V55);
c) 81a^4-1=(9a^2-1)(9a^2+1)=(3a-1)*(3a+1)*(9a^2+1);
d) y^2-x^2-6x-9=y^2-(x+3)^2=(y-x-3)*(y+x+3).