Câu hỏi của Hoàng Ngọc Linh

Question

Tính nhanh: (18.123+9.436.2+3.5310.6) : ( 1+4+7+...+100-410 )

Nguyễn Ngọc Minh Châu · Accepted Answer

Ta có:

+) $1+4+7+...+100=\left(1+100\right)+\left(4+97\right)+...+\left(49+52\right)$(34 cặp)

$=101.34=3434$

+) $3434-410=3024$

+) $\left(18.123+9.436.2+3.5310.6\right)=18\left(123+436+5310\right)$

$=18.5869=105642$

Vậy $A=105642:3024\approx34,93$Câu trả lời: Ta có:

+) $1+4+7+...+100=\left(1+100\right)+\left(4+97\right)+...+\left(49+52\right)$(34 cặp)

$=101.34=3434$

+) $3434-410=3024$

+) $\left(18.123+9.436.2+3.5310.6\right)=18\left(123+436+5310\right)$

$=18.5869=105642$

Vậy $A=105642:3024\approx34,93$