Question

Tính  A=1/(1*2*3)+1/(2*3*4)+1/(3*4*5)+...+1/(48*49*50)

Answer 1

Ax2=1x2/1x2x3+1x2/2x3x4+...+1x2/48x49x50

Ax2=1/1x2-1/2x3+1/2x3-1/3x4+...+1/48x49-1/49x50

Ax2=1/1x2-1/49x50

Ax2=1/2-1/2450

Ax2=1225/2450-1/2450

Ax2=1224/2450

A=1224/2450:2

A=1224/2450X1/2

A=1224/4900

A=306/1225

Answer 2

Còn câu trả lời nào khác ko zậy !?!

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