Question

[Ngọc Linh Phạm]

5/2+5/6+5/18+5/54+5/162

mọi người ơi nhanh giùm mình

Answer 1

[when the imposter is sus]

Gọi giá trị của biểu thức trên là A. Ta có:

\(A=\dfrac{5}{2}+\dfrac{5}{6}+\dfrac{5}{18}+\dfrac{5}{54}+\dfrac{5}{162}\)

\(3A=\dfrac{15}{2}+\dfrac{5}{2}+\dfrac{5}{6}+\dfrac{5}{18}+\dfrac{5}{54}\)

\(3A-A=\left(\dfrac{15}{2}+\dfrac{5}{2}+\dfrac{5}{6}+\dfrac{5}{18}+\dfrac{5}{54}\right)-\left(\dfrac{5}{2}+\dfrac{5}{6}+\dfrac{5}{18}+\dfrac{5}{54}+\dfrac{5}{162}\right)\)

\(2A=\dfrac{15}{2}-\dfrac{5}{162}\)

\(A=\left(\dfrac{15}{2}-\dfrac{5}{162}\right)\div2=\dfrac{605}{81}\div2=\dfrac{605}{162}\)

Answer 2

[DSQUARED2 K9A2]

= 10/3 + 5/18 + 5/54 + 5/162

= 65/18 + 5/54 + 5/162

= 100/27 + 5/162

= 605/162