231=3*4*11 217=7*31
НОД=7 НОК=231*31=7161
242=2*11*11 642=2*3*107
НОД=2 НОК=642*121=77682
999=3*3*3*37 666=2*3*3*37
НОД=333 НОК=999*2=1998
6) 0,0001 * 0,1⁵ = 10⁻⁴ * (10⁻¹)⁵ = 10⁻⁴ * 10⁻⁵ = 10⁻⁴⁻⁵ =10⁻⁹
b)25x²-10xy+y²+15x-3y=(5x-y)²+3(5x-y)=(5x-y)*(5x-y+3)
c)a³-27+6a²-18a=(a-3)*(a²+3a+9)+6a*(a-3)=(a-3)*(a²+3a+9+6a)=(a-3)*(a²+9a+9)
Cos(0.5x)*cos(x)-0.5*sin(0.5*x)*sin(x);