Question

so sánh không quy đồng A= \(\frac{-7}{10^{2014}}+\frac{-15}{10^{2015}}\)

                                     B=\(\frac{-15}{10^{2014}}+\frac{-7}{10^{2015}}\)

Answer 1

A= \(\frac{8-15}{10^{2014}}+\frac{-15}{10^{2015}}=\frac{8}{10^{2014}}-15.\left(\frac{1}{10^{2014}}+\frac{1}{10^{2015}}\right)\)

B=\(\frac{-15}{10^{2014}}+\frac{8-15}{10^{2015}}=\frac{8}{10^{2015}}-15.\left(\frac{1}{10^{2014}}+\frac{1}{10^{2015}}\right)\)

Nhận xét: \(\frac{8}{10^{2015}}

Answer 2

B < A

mới lập níc,k cho mình nhá!

Answer 3

\(A=\frac{8-15}{10^{2014}}+\frac{-15}{10^{2015}}=\frac{8}{10^{2014}}-15.\left(\frac{1}{10^{2014}}+\frac{1}{10^{2015}}\right)\)

\(B=\frac{-15}{10^{2014}}+\frac{8-15}{10^{2015}}=\frac{8}{10^{2015}}-15.\left(\frac{1}{10^{2014}}+\frac{1}{10^{2015}}\right)\)

Ta có nhận xét :

\(\frac{8}{10^{2015}}< \frac{8}{10^{2014}}\Rightarrow\frac{8}{10^{2015}}-15.\left(\frac{1}{10^{2014}}+\frac{1}{10^{2015}}\right)< \frac{8}{10^{2014}}-15.\left(\frac{1}{10^{2014}}+\frac{1}{10^{2015}}\right)\)

\(\Rightarrow B< A\)