The decomposition coefficient is as follows:
(x+y)？ -4(x？ -Really? )+4(x-y)？ =(x+y)？ -4(x+y)(x-y)+4(x-y)？ =(x+y-2(x-y))？
=(3y-x)？
2. What are the shapes of chicken farms and pig farms? This is very important. If it's a square, it's ok, but other graphics are not. If it is a square, the solution is as follows:
What is the area of the pig farm? What is the area of chicken farm? According to the meaning of the problem, the equation can be listed as
x？ -Really? =60
4x+4y=60
X+y= 15 from 4x+4y=60, and x? -Really? =60
So x-y =4, the solution is X = 19/2, and Y = 1 1/2.
x？ =36 1/4，y？ = 12 1/4
Answer: The pig farm area is 36 1/4, and the chicken farm area is 12 1/4.
3、4(m-n)？ -9(m+n)？ =〔2(m-n)+3(m+n)〕〔2(m-n)-3(m+n)〕〔=(2m-2n+3m+3n)(2m-2n-3m-3n)=-(5m-n)(m+n)
(m+n)？ +(m+n)(m-3n)=(m+n)(m+n+m-3n)=(m+n)(2m-2n)= 2(m+n)(m-n)