Question

So sánh:

a) \(\frac{-2525}{2929}\) và \(\frac{-217}{245}\) 

b) \(\frac{27}{82}\) và \(\frac{26}{75}\) 

c) A= \(\frac{3^{10}+1}{3^9+1}\) và B= \(\frac{3^9+1}{3^8+1}\)

Answer 1

A=\(\frac{3^{10}+1}{3^9+1}\)>1  

=> A=\(\frac{3^{10}+1}{3^9+1}\)> \(\frac{3^{10}+1+2}{3^9+1+2}\)

=>A=\(\frac{3^{10}+1}{3^9+1}\)>\(\frac{3^{10}+3}{3^9+3}\)

=>A=\(\frac{3^{10}+1}{3^9+1}\)>\(\frac{3\left(3^9+1\right)}{3.\left(3^8+1\right)}\)

=>A=\(\frac{3^{10}+1}{3^9+1}\)>\(\frac{3^9+1}{3^8+1}\)=B

vậy A>B

Answer 2

vì 1 là bạn quy đồng lên 

 hai là giải thich như sau

 \(\frac{25}{29}\)= 1- \(\frac{4}{29}\)

\(\frac{31}{35}\)= 1- \(\frac{4}{35}\)   mà \(\frac{4}{29}\)> \(\frac{4}{35}\)

nên 1-\(\frac{4}{29}\)<1-\(\frac{4}{35}\)

vậy \(\frac{25}{29}\)<\(\frac{31}{35}\)

Answer 3

a. \(\frac{-2525}{2929}\)= -\(\frac{25.101}{29.101}\)=\(\frac{-25}{29}\)

\(\frac{-217}{245}\)=\(\frac{-7.31}{7.35}\)=\(\frac{-31}{35}\)

vì \(\frac{25}{29}\)>\(\frac{31}{35}\) => \(\frac{-25}{29}\)<\(\frac{-31}{35}\)

b.ta có 27.75=2025

26.82=2132

=> 26.82> 27.75

vậy \(\frac{27}{82}\)<\(\frac{26}{75}\)

Answer 4

Mai Linh cho mình hỏi bạn lm cách nào mà ra đc 25/29>31/35 z ?

Answer 5

à quên \(\frac{25}{29}\)<\(\frac{31}{35}\)=> \(\frac{-25}{29}\)>\(\frac{-31}{35}\)