Câu hỏi của HLinhh

Question

Tính: 1/45 + 2/45 +3/45 + ... + 9/45

Nguyễn Thị Thương Hoài · Accepted Answer

A = $\dfrac{1}{45}$ + $\dfrac{2}{45}$ + $\dfrac{3}{45}$+...+ $\dfrac{9}{45}$

A = $\dfrac{1+2+3+...+9}{45}$

A =  $\dfrac{\left(1+9\right)\times9:2}{45}$

A = $\dfrac{45}{45}$

A =1Câu trả lời: A = $\dfrac{1}{45}$ + $\dfrac{2}{45}$ + $\dfrac{3}{45}$+...+ $\dfrac{9}{45}$

A = $\dfrac{1+2+3+...+9}{45}$

A =  $\dfrac{\left(1+9\right)\times9:2}{45}$

A = $\dfrac{45}{45}$

A =1