Question

B=1+2-3-4+...+251+252-253-254

Answer 1

Ta có: B=1+2-3-4+...+251+252-253-254

=(1-2-3+4)+(5-6-7+8)+...+(251-252-253+254)

= 0+0+...+0

=0

Answer 2

\(B=1+2-3-4+...+251+252-253-254\) 

\(B=\left(1+2-3-4\right)+...+\left(251+252-253-254\right)\) 

\(B=-4+...+\left(-4\right)\) 

\(B=-4.63,5\) 

\(B=-254\)