2-1/3=1+1-1/3=1+(3/3 - 1/3)=1+ 2/3 = 1 2/3
5a^6 -15a^4= 5a^4(a^2 - 3) =5a^4(a-√3)(a+√3)
................................
А) (xy-1)<em />·(xy+1)
б)(5-6cp)·(6cp+5)
в)(2-cd)·(cd+2)
г)(7xy-20)·(7xy+20)
<span>-8а^6b(2а^3)^5=
-8а^6b*32a^15=
=-256a^21b</span>