\(A=100+98+96+...+2-97-95-...1\)
\(A=100+\left(98-97\right)+\left(96-95\right)+...\left(2-1\right)\)
\(A=100+1+1+1+...+1\)
\(A=100+1.49\)
\(A=100+49\)
\(A=149\)
A =100+(98-97)+(96-95)+(94-93)+…+(2-1) ( Có 98:2=49( cặp hiệu) = 100+1+1+1+…+1(49 số hạng 1)
= 100+1×49
= 100+49
= 149
\(B=1+2-3-4+5+6-...-299-300+301+302\)
\(B=\left(1+2-3\right)+\left(-4+5+6-7\right)+...+\left(298-299-300+301\right)+302\)
\(B=0+0+0+0+...+0+302\)
\(B=302\)
A=100+98+96+...+2-97-95-...-1
A=100+(98-97)+(96-95)+....+(2-1)
A=100+1.49
A=100+49
A =149
