Question

Tính :

a ) ( a + b ) - ( - c + a + b )

b ) -(x + y ) + ( -Z + x + y )
c) ( m - n + p ) + ( -m + n + p )
Giúp nhaa

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Helpp mee

Answer 1

\(\left(a+b\right)-\left(-c+a+b\right)\)

\(=a+b+c-a-b\)

\(=\left(a-a\right)+\left(b-b\right)+c\)

\(=c\)

\(-\left(x+y\right)+\left(-z+x+y\right)\)

\(=-x+-y+-z+x+y\)

\(=\left[\left(-x\right)+x\right]+\left[\left(-y\right)+y\right]+-z\)

\(=-z\)

\(\left(m-n+p\right)+\left(-m+n+p\right)\)

\(=m-n+p-m+n+p\)

\(=\left(m-m\right)+\left(n-n\right)+\left(p+p\right)\)

\(=2p\)