Question

.已知m的平方=n+2,n的平方=m+2,求m的平方+2mn+n的平方

Answer 1

m^2=n+2

n^2=m+2

1 m=n

m^2-m-2=0 (m-2)(m+1)=0

m1=2 m^2+2mn+n^2=(m+n)^2=4^2=16

m2=-1 (m+n)^2=(-2)^2=4

2 m不等于n

m^2-n^2=n-m

(m+n)(m-n)=n-m

m+n=-1

m^2+2mn+n^2=(m+n)^2=1.