\(A=-1-2-3-4-...-49-50\)
\(=\left[-50+\left(-1\right)\right].50:2\)
\(=-1275\)
A = - 1 - 2 - 3 - 4 - ......- 49 - 50
A = [ - 50 + ( - 1 ) ]. 50 : 2
A = - 1275
ai tk mình mình tk lại cho
=[1-2]-[3-4]-...[49-50] =[-1]-[-1]-...[-1] =ta thay tu 1---- 50 co 50 so =c0 25 cap =[-1]-[-1]-...-[-1] =(-1).25 =[-25]