SOS!?!??!!!!!! Не понять​

1)= (х+4)·(х²-20х+100)=(х+4)·(х-10)²

2) = - (36-a²) - 2a(36-a²) - a²(36-a²)=  (36-a²)·( -1 - 2a - a²) =

= - (36-a²)·(a+1)²=(a²-36)·(a+1)²=(a-6)(a+6)(a+1)²

3) = a²b-a²-b²a+b² =( a²b - b²a) - (a² - b²)= ab·(a-b)-(a-b)·(a+b)=

=(a-b)·(ab-a-b)

4)=(m-n)·(n-p)·(n²+np+p²)-(n-p)·(m-n)·(m²+mn+n²)=

=(m-n)·(n-p)·(n²+np+p²-m²-mn-n²)=

= (m-n)·(n-p)·(p²-m²+np-mn)=(m-n)·(n-p)·((p-m)·(p+m)+n·(p-m))=

=(m-n)·(n-p)·(p-m)·(p+m+n)