1) (а-12)³ - 125=(a-12)³-5³=(a-12-5)((a-12)²+(a-12)*5+5²)=
=(a-17)(a²-24a+144+5a-60+25)=
=(a-17)(a²-19a+109)
2)(b+4)³+64=(b+4)³+4³=(b+3+4)((b+3)²+(b+3)*4+4²)=
=(b+7)(b²+6b+9+4b+12+16)=
=(b+7)(b²+10b+37)
3)81-(с²+6с)²=9²-(c²+6c)²=(9+c²+6c)(9-c²-6c)=(c+3)²(9-c²-6c)
<span>4)16m</span>²<span>-(m-n)</span>²=(4m)²-(m-n)²=(4m+m-n)(4m-m+n)=(5m-n)(3m+n)
Биквадратное уравнение))
Пусть x^2 = t, тогда 3t^2 - 8t - 3 = 0
D= 64 + 36 = 100
x1 = (8-10)/6 = - 1/3
x2 = (8+10)/6 = 18/6 = 3
x^2 = 3 ==> x = ± √3
ОТВЕТ:
x = ± √3