Question

Chứng minh đẳng thức -(-a+b+c)+(b+c-1)=(b-c+6)-(7-a+b)+c

Answer 1

Ta có:

-(-a+b+c)+(b+c-1)

=a-b-c+b+c-1

=(b-b)+(c-c)+a-1

=0+0+a-1

=a-1

(b-c+6)-(7-a+b)+c

=b-c+6-7+a-b+c

=(b-b)+(c-c)+a+[(-7)+6]

=0+0+a-1

=a-1

Vì a-1=a-1

=>-(-a+b+c)+(b+c-1)=(b-c+6)-(7-a+b)-c

Answer 2

Ta có:

-(-a+b+c)+(b+c-1)

=a-b-c+b+c-1

=(b-b)+(c-c)+a-1

=0+0+a-1

=a-1

(b-c+6)-(7-a+b)+c

=b-c+6-7+a-b+c

=(b-b)+(c-c)+a+[(-7)+6]

=0+0+a-1

=a-1

Vì a-1=a-1

=>-(-a+b+c)+(b+c-1)=(b-c+6)-(7-a+b)-c

Answer 3

thank nha bạm

Answer 4

cảm ơn bạn nha

Answer 5

cảm ơn bạn nha.

Answer 6

-(-a+b+c)+(b+c-1)=(b-c+6)-(7-a+b)+c

=>a-b-c+b+c-1=b-c+6-7+a-b+c

=>a-1=6-7+a

=>a-1=-1+a=a-1

Answer 7

Thanks very much!

Answer 8

\(VT=-\left(-a+b+c\right)+\left(b+c-1\right)=a-b-c+b+c-1=-1+a\)

\(VP=\left(b-c+6\right)-\left(7-a+b\right)+c=b-c+6-7+a-b+c=-1+a\)

Vì \(-1+a\left(VT\right)=-1+a\left(VP\right)\Rightarrow VT=VP\left(đpcm\right)\)

Answer 9

Thanks các bạn nha