407. а)х³-у³ б)125-а³ в)8m³-125n³ u) 343p³+q³ д)1/8x³-1/27y³ e) 0.001a³-0.008b³
409. (m-1)(m²+m+1) (p-3q)(p²+3pq+9q²) (5x-2y)(25x²+10xy+4y²)
(4a+10b)(16a²-40ab+100b²) (x²-y²)(x⁴+x²y²+y⁴) (m⁴-4)(m⁸+4m⁴+16)
(x³-y²)(x⁶+x³y²+y⁴) (c²d-k)(c⁴d²+c²dk+k²)
411. x³-1-x³-1=-2
a⁶-27+a⁴(1-a²)=a⁶-27+a⁴-a⁶=a⁴-27
2p²(8-p³)-4(p²-25)=16p²-2p⁵-4p²+100=8p²-p⁵-2p²+50=6p²-p⁵+50
n⁵(n⁴-4)-(m³-n⁹)=n⁹-4n⁵-m³+n⁹=2n⁰-4n⁵+m³