X^2-64x=0 x(x-64)=0
x1=0 x-64=0 x2=64
a)-12a^2+18a^3=-6a^2(2-3a)
b)2a+4b-ab-2b^2=a(2-b)+2b(2-b)=(a+2b)(2-b)
в)x^2-64y^2=(x+8y)(x-8y)
г)-2x^3-28x^2-98x=-2x(x^2+14x+49)=-2x(x+7)^2
a)(49m^2-n^2)/(3mn^2-21m^2n)=(7m+n)(7m-n)/3mn(n-7m)=-(7m+n)/3mn;
b)(81x^2-16)/(16+72x+81x^2)=(9x+4)(9x-4)/(9x+4)(9x+4)=(9x-4)/(9x+4);
3)(x-4)^2-25=0
x^2-8x+16-25=0
x^2-8x-9=0
x1=4+√16+9=4+5=9 x2=4-√25=4-5=-1
x1=9,x2=-1.
4)x^2-12x+45=(x-15)(x+3) -12x=15x+3x
x^2-12x+45=x^2-15x+3x+45=x(x+3)-15(x+3)=(x-15)(x+3).
5) (99^2-61^2)/38+99*61=((100-1)^2-(62-1)^2)/(100-62) +(100-1)(60+1)=
=(100^2-2*100+1-62^2+2*62-1)/(100-62) +(100-1)(60+1)=
=(100^2-62^2-2(100-62)/(100-62) +(100-1)(60+1)=
=((100-62)(100+62)-2(100-62))/(100-62) +(100-1)(60+1)=
=(100+62-2)+100*60-60+100-1=100+60+100*60-60+100-1=200+6000-1=6199.