Question

rut gon bieu thuc

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

Answer 1

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

=[ ( -a ) + a ] + b - b + c + c

= 0 + ( b-b ) + ( c+c )

=0+0+  2x

=2x

Answer 2

(-a-b+c)-(-a-b-c)=-a-b+c+a+b+c=2c

Answer 3

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

=-a-b+c+a+b+c

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

=0+0+c.2

=c2