K
Khách

Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.

11 tháng 8 2019

\(a,\frac{125\cdot81\cdot7}{49\cdot75\cdot27}=\frac{25\cdot5\cdot9\cdot9\cdot7}{7\cdot7\cdot15\cdot5\cdot3\cdot9}=\frac{25\cdot9}{7\cdot15\cdot3}=\frac{5\cdot5\cdot3\cdot3}{7\cdot3\cdot5\cdot3}=\frac{5}{7}\)

\(b,\frac{48\cdot25-48\cdot11-48}{16\cdot23-16\cdot10}=\frac{1200-528-48}{368-160}=\frac{624}{208}=3\)

\(c,\frac{15\cdot\left[4\cdot17+17\cdot5\right]}{18\cdot25\cdot34}=\frac{15\cdot\left[17\cdot\left(4+5\right)\right]}{15300}=\frac{15\cdot153}{15300}\)

\(=\frac{2295}{15300}=\frac{3}{20}\)

\(d,\frac{1996\cdot1995-996}{1000+1996\cdot1994}=\frac{3982020-996}{1000+3980024}=\frac{3981024}{3981024}=1\)

17 tháng 8 2018

\(\frac{1995.1993-18}{1975.1993.1994}\)\(=\frac{1995-18}{1975.1994}\)

                                      \(=\frac{1977}{1975.1994}\)

                                      \(=\frac{1975+2}{1975.1994}\)

                                      \(=\frac{2}{1994}=\frac{1}{997}\)

\(\frac{1996.1995-996}{1000+1996.1994}\)\(=\frac{1995-996}{1994+1000}\)

                                           \(=\frac{999}{1994+1000}\)

                                           \(=\frac{999}{1994+999+1}\)

                                          \(=\frac{1}{1994+1}=\frac{1}{1995}\)

                                         

26 tháng 7 2017

1996*1995-1996*1994=1996

(1996*1995-996)-(1996*1994)=1996-996=1000

(1996*1995-996)-(1996*1994+1000)=1996-996-1000=0

=>(1996*1995-996)/(1996*1994+1000)=1( vì tử số bằng mẫu số)

26 tháng 7 2017

\(\frac{1996.1995-996}{1996.1994+1000}=\frac{\left(1000+996\right).1995-996}{\left(1000+996\right).1994+1000}\)

\(=\frac{1000.1995+996.1995-996}{996.1994+1000.1994+1000}=\frac{1000.1995+996\left(1995-1\right)}{996.1994+1000\left(1994+1\right)}\)

\(=\frac{1000.1995+996.1994}{996.1994+1000.1995}\)=1

1 tháng 4 2022

\(\dfrac{1996.1995-996}{1000+1996.1994}=\dfrac{1996\left(1994+1\right)-996}{1000+1996.1994}=\dfrac{1996.1994+1996-996}{1000+1996.1994}\) 

\(=\dfrac{1000+1996.1994}{1000+1996.1994}=1\)

28 tháng 10 2019

1)

a) \(\left(-48\right)^3:16^3\)

\(=\left(-48:16\right)^3\)

\(=\left(-3\right)^3\)

\(=-27.\)

b) \(\left(\frac{9}{10}\right)^6:\left(\frac{17}{-20}\right)^6\)

\(=\left(\frac{9}{10}:\frac{17}{-20}\right)^6\)

\(=\left(-\frac{18}{17}\right)^6\)

Chúc em học tốt!

28 tháng 10 2019

\(\frac{-13^3}{\left(2^3\right)^3}:\frac{\left(-2^5\right)^4}{13^4}\)1.

a, (-48)3:163

= \(\left(\frac{-48}{16}\right)^3\)

= (-3)3

b,\(\left(\frac{9}{10}\right)^6\):\(\left(\frac{17}{-20}\right)^6\)

= \(\left(\frac{9}{10}:\frac{17}{-20}\right)^6\)

=\(\left(\frac{-18}{17}\right)^6\)

c, \(\left(\frac{-13}{8}\right)^3:\left(\frac{-32}{13}\right)^4\)

= \(\frac{-13^3}{\left(2^3\right)^3}:\frac{\left(-2^5\right)^4}{13^4}\)

= \(\frac{-13^3}{2^9}.\frac{-13^4}{2^{20}}\)

=\(\frac{13^7}{2^{29}}\)

11 tháng 10 2017

tham khao nha

\(A=\left(\frac{\sqrt{a}}{\sqrt{ab}-b}+\frac{2\sqrt{a}+\sqrt{b}}{\sqrt{ab}-a}\right):\left(\frac{1}{\sqrt{a}}+\frac{1}{\sqrt{b}}\right)\)

\(A=\left(\frac{\sqrt{a}}{\sqrt{b}\left(\sqrt{a}-\sqrt{b}\right)}+\frac{2\sqrt{a}+\sqrt{b}}{\sqrt{a}\left(\sqrt{b}-\sqrt{a}\right)}\right):\left(\frac{\sqrt{b}+\sqrt{a}}{\sqrt{ab}}\right)\)

\(A=\left(\frac{\sqrt{a}}{\sqrt{b}\left(\sqrt{a}-\sqrt{b}\right)}-\frac{2\sqrt{a}+\sqrt{b}}{\sqrt{a}\left(\sqrt{a}-\sqrt{b}\right)}\right).\frac{\sqrt{ab}}{\sqrt{b}+\sqrt{a}}\)

\(A=\frac{a-2\sqrt{ab}+b}{\sqrt{ab}\left(\sqrt{a}-\sqrt{b}\right)}.\frac{\sqrt{ab}}{\sqrt{b}+\sqrt{a}}\)

\(A=\frac{\left(\sqrt{a}-\sqrt{b}\right)^2}{\sqrt{ab}\left(\sqrt{a}-\sqrt{b}\right)}.\frac{\sqrt{ab}}{\sqrt{b}+\sqrt{a}}\)

\(A=\frac{\sqrt{a}-\sqrt{b}}{\sqrt{a}+\sqrt{b}}\)

vay \(A=\frac{\sqrt{a}-\sqrt{b}}{\sqrt{a}+\sqrt{b}}\)

ĐK : tự ghi nha

\(\left(\frac{\sqrt{a}}{\sqrt{ab}-b}+\frac{2\sqrt{a}+\sqrt{b}}{\sqrt{ab}-a}\right):\left(\frac{1}{\sqrt{a}}+\frac{1}{\sqrt{b}}\right)\)