Câu hỏi của Hany Han

Question

Tính nhanh :A=$\dfrac{15}{34}+\dfrac{7}{21}+\dfrac{9}{34}-1\dfrac{15}{17}+\dfrac{2}{3}$

Nguyen Ngoc Anh Linh · Accepted Answer

$A=\dfrac{15}{34}+\dfrac{1}{3}+\dfrac{9}{34}-\dfrac{32}{17}+\dfrac{2}{3}$

$A=\dfrac{15}{34}+\dfrac{1}{3}+\dfrac{9}{34}-\dfrac{64}{34}+\dfrac{2}{3}$

$A=\left(\dfrac{15}{34}+\dfrac{9}{34}-\dfrac{64}{34}\right)+\left(\dfrac{1}{3}+\dfrac{2}{3}\right)$

$A=\dfrac{40}{34}+1=2\dfrac{6}{34}$Câu trả lời: $A=\dfrac{15}{34}+\dfrac{1}{3}+\dfrac{9}{34}-\dfrac{32}{17}+\dfrac{2}{3}$

$A=\dfrac{15}{34}+\dfrac{1}{3}+\dfrac{9}{34}-\dfrac{64}{34}+\dfrac{2}{3}$

$A=\left(\dfrac{15}{34}+\dfrac{9}{34}-\dfrac{64}{34}\right)+\left(\dfrac{1}{3}+\dfrac{2}{3}\right)$

$A=\dfrac{40}{34}+1=2\dfrac{6}{34}$

Nguyễn Thanh Hằng · Answer

$A=\dfrac{15}{34}+\dfrac{7}{21}+\dfrac{9}{34}-1\dfrac{15}{17}+\dfrac{2}{3}$

$=\dfrac{15}{34}+\dfrac{1}{3}+\dfrac{9}{34}-1\dfrac{15}{17}+\dfrac{2}{3}$

$=\left(\dfrac{15}{34}+\dfrac{9}{34}\right)+\left(\dfrac{1}{3}+\dfrac{2}{3}\right)-1\dfrac{15}{17}$

$=1+1-1\dfrac{15}{17}$

$=2-1\dfrac{15}{17}$

$=\dfrac{2}{17}$Câu trả lời: $A=\dfrac{15}{34}+\dfrac{7}{21}+\dfrac{9}{34}-1\dfrac{15}{17}+\dfrac{2}{3}$

$=\dfrac{15}{34}+\dfrac{1}{3}+\dfrac{9}{34}-1\dfrac{15}{17}+\dfrac{2}{3}$

$=\left(\dfrac{15}{34}+\dfrac{9}{34}\right)+\left(\dfrac{1}{3}+\dfrac{2}{3}\right)-1\dfrac{15}{17}$

$=1+1-1\dfrac{15}{17}$

$=2-1\dfrac{15}{17}$

$=\dfrac{2}{17}$

Chương I : Số hữu tỉ. Số thực