a, M + N = \(\left(x^2-2xy+y^2\right)+\left(y^2+2xy+x^2+1\right)\)
=\(2x^2+2y^2+1\)
b,M - N =\(\left(x^2-2xy+y^2\right)-\left(y^2+2xy+x^2+1\right)\)
=\(-4xy-1\)
\(M+N=\left(x^2-2xy+y^2\right)+\left(y^2+2xy+x^2+1\right)\)
\(\Rightarrow M+N=2x^2+2y^2+1\)
\(M-N=\left(x^2-2xy+y^2\right)-\left(y^2+2xy+x^2+1\right)\)
\(\Rightarrow M-N=-4xy-1\)
tíc mình nha
\(a.M+N=\left(x^2-2xy+y^2\right)+\left(y^2+2xy+x^2+1\right)\)
\(=x^2-2xy+y^2+y^2+2xy+x^2+1\)
\(=\left(x^2+x^2\right)+\left(-2xy+2xy\right)+\left(y^2+y^2\right)+1\)
\(=2x^2+2y^2+1\)
\(b.M-N=\left(x^2-2xy+y^2\right)-\left(y^2+2xy+x^2+1\right)\)
\(=x^2-2xy+y^2-y^2-2xy-x^2-1\)
\(=\left(x^2-x^2\right)+\left(-2xy-2xy\right)+\left(y^2-y^2\right)-1\)
\(=-4xy-1\)
T mk nhé bn ^...^ ^_^
a) => M +N = \(x^2-2xy+y^2+y^2+2xy+x^2+1\)
\(=2x^2+2y^2+1\)
\(=2\left(x^2+y^2\right)+1\)
b) => M-N = \(x^2-2xy+y^2-y^2-2xy-x^2-1\)
\(=\left(-4xy\right)-1\)
a) M + N = ( x^2 - 2xy + y^2 ) + ( y^2 + 2xy + x^2 + 1 )
= ( x^2 + x^2 ) + ( y^2 + y^2 ) + ( - 2xy + 2xy ) + 1
= 2x^2 + 2y^2 + 1
b) M - N = ( x^2 - 2xy + y^2 ) - ( y^2 + 2xy + x^2 + 1 )
= ( x^2 - x^2 ) + ( - 2xy - 2xy ) + ( y^2 - y^2 ) + 1
= - 4xy + 1