Câu hỏi của son goku

Question

1/15+4/30+9/45+16/60+25/75+36/90+49/105+64/120+81/135

Quang Huy Điền · Accepted Answer

$=\dfrac{1}{15}+\dfrac{2}{15}+\dfrac{3}{15}+...+\dfrac{9}{15}$

$=\dfrac{1+2+3+...+9}{15}$

$=\dfrac{45}{15}=3$Câu trả lời: $=\dfrac{1}{15}+\dfrac{2}{15}+\dfrac{3}{15}+...+\dfrac{9}{15}$

$=\dfrac{1+2+3+...+9}{15}$

$=\dfrac{45}{15}=3$