1/2 + 1/6 + 1/12 + 1/20 + 1/30 + 1/42 + 1/56 +
1/2+1/6+1/12+1/20+1/30+1/42+1/56
1/2 + 1/6 + 1/12 + 1/20 + 1/30 + 1/42 + 1/56
A= 1/2+1/6 +1/12+1/20+1/30+1/42+1/56
1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72=????
a ) 12,8 x 195 + 12,8 x 804 + 12,8
b) 1/2 +1/6 + 1/12+ 1/20+ 1/30 +1/42 +1/56 +1/72+ 1/90
1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72 = ?
1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/90+1/110 = ?
1/90-1/72-1/56-1/42-1/30-1/20-1/12-1/6-1/2