9/10-1/90-1/72-1/56-1/42-1/30-1/20-1/12-1/6-1/2 = ?
9/10 +1/90++1/72+1/56+1/42+1/30+1/20+1/12+1/6+1/2
Tính D biết 1/90-1/72-1/56-1/42-1/30-1/20-1/12-1/6-1/2 = ?
-1/90-1/72-1/56-1/42-1/30-1/20-1/12-1/6-1/2 . Tính hợp lí
A= 1/6 + 1/12 + 1/20 + 1/30 + 1/42 + 1/56 + 1/72 + 1/90
tính hợp lí :1/100 -1/90-1/72-1/56-1/42-1/30-1/20-1/12-1/6-1/2
tính :
bB= 1/90 - 1/72 - 1/56 - 1/42 - 1/30 - 1/20 -1/12 - 1/6 - 1/2
Tính : B=1/90-1/72-1/56-1/42-1/30-1/20-1/6-1/12
A = 1/6 + 1/12 + 1/20 + 1/30 + 1/42 + 1/56 + 1/72 + 1/90 + 1/110=?