N°5.88
1)=a³+b³-2aba-2ab×b=a³+b³-2a²b-2ab²
2)=m³-n³-6m³-6m²n-6mn²=-5m³-n³-6m²n-6mn²
3)=(x-y)×(x²+xy+y²)+8xy×(x-y)=(x-y)(x²+9xy+y²)
4)=p³+q³-2p³q+2p²q²-2pq³
N°5.89
1)=(2a+1)(4a²-2a+1)+3a(2a+1)=(2a+1)(4a²+a+1)
2)=(x-5)(x²+5x+25)-4x(x-5)=(x-5)(x²+x+25)
3)=m(m³+n³)-n(m³+n³)=(m+n)(m²-mn+n²)(m-n)
4)=c³(c+y)-y³(c+y)=(c+y)(c-y)(c²+cy+y²)