Question

1.（m+n)(n-m)-n(m+n)(m-n) 2. 3a(x-y)-(x-y)a 3. (x-y)²-2（y-x) 4.（m+n)(p+q)-(m+n)(q+p)

5.m（x-y)²-x+y
5(y-x)²+3（x-y) 15*（a-b)²-3y(b-a) 6(m-n)³-12（n-m)²

Answer 1

1.（m+n)(n-m)-n(m+n)(m-n)
=(m+n)(n-m)-n(m+n)[-(n-m)]
=(m+n)(n-m)+n(m+n)(n-m)
=(m+n)(n-m)(1+n)

2. 3a(x-y)-(x-y)a
=(x-y)(3a-a)
=2a(x-y)

3. (x-y)²-2（y-x)
=(x-y)²-2[-(x-y)]
=(x-y)²+2(x-y)
=(x-y)(x-y+2)

4.（m+n)(p+q)-(m+n)(q+p)
=(m+n)(p+q)-(m+n)(p+q)
=0

5.m（x-y)²-x+y
=m(x-y)²-(x-y)
=(x-y)[m(x-y)-1]
=(x-y)(mx-my-1)