Question

帮忙解答几道七年级计算题，请写下完整步骤，谢谢！

1）（-5m-4n)^2
2）(m+n)^2-2(m+1)(m-1)+4(m-n)^2
3)2a(m-n)-4b(n-m)
^2表示2的平方

Answer 1

1)25m^2+40mn+16n^4
2)m^2+2mn+n^2-2m^2+2+4m^2-8mn+4n^2=3m^2-6mn+5n^2+2
3)(2a+4b)(m-n)

Answer 2

1）(-5m-4n)^2=(5m+4n)^2=25m^2+40mn+16n^2
2),(m+n)^2-2（m+1))(m-1)+4(m-n)^2
=m^2+2mn+n^2-2m^2+2+4m^2-8mn+4n^2
=3m^2-6mn+5n^2+2
3),2a(m-n)-4b(n-m)
=2am-2an-4bn+4bm

Answer 3

1)原式=25m^2+40mn+16n^2
2)原式=m^2+2mn+n^2-2m^2-2+4m^2-8nm+4n^2
=3m^2-6mn+5n^2-2
3)原式=2a(m-n)+4b(m-n)
=(m-n)(2a+4b)

Answer 4

1\25M^2+16N^2+20MN
2\
3\(m-n)(2A+4B)=

追问

请写下完整步骤