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28 tháng 6 2019

a) Ta có:

C = 5/18 + 8/19 - 7/21 + (-10/36 + 11/19 + 1/3) - 5/8

C = 5/18 + 8/19 - 1/3 - 5/18 + 11/19 + 1/3 - 5/8

C = (5/18 - 5/18) + (8/19 + 11/19) - (1/3  - 1/3) - 5/8

C = 1 - 5/8

c = 3/8

b) F = 15/14 - (17/23 - 80/87 + 5/4) + (17/23 - 15/14 + 1/4)

F = 15/14 - 17/23 + 80/87 - 5/4 + 17/23 - 15/14 + 1/4

F = (15/14 - 15/14) - (17/23 - 17/23) + 80/87 - (5/4 - 1/4)

F = 80/87 - 1

F = -7/87

c) G = 1/25 - 4/27 + (-23/27 + -1/25 - 5/43) + 5/43 - 4/7

G = 1/25 - 4/27 - 23/27 - 1/25 - 5/43 + 5/43 - 4/7

G = (1/25 - 1/25) - (4/27 + 23/27) - (5/43 - 5/43) - 4/7

G = -1 - 4/7 = -11/7

23 tháng 7 2016

\(H=\frac{4}{15}-\frac{23}{28}-\left(-\frac{23}{28}+\frac{-11}{15}-\frac{24}{27}\right)-\frac{2}{27}\)

\(H=\frac{4}{15}+\frac{-23}{28}+\frac{23}{28}+\frac{11}{15}+\frac{24}{27}+\frac{-2}{27}\)

\(H=\left(\frac{4}{15}+\frac{11}{15}\right)+\left(\frac{-23}{28}+\frac{23}{28}\right)+\left(\frac{24}{27}+\frac{-2}{27}\right)\)

\(H=1+0+\frac{22}{27}\)

\(H=1+\frac{22}{27}\)

\(H=\frac{27}{27}+\frac{22}{27}=\frac{49}{27}\)

23 tháng 7 2016

\(H=\frac{4}{15}-\frac{23}{28}-\left(\frac{-23}{28}+\frac{-11}{15}-\frac{24}{27}\right)-\frac{2}{27}\)

\(H=\frac{4}{15}-\frac{23}{28}+\frac{23}{28}+\frac{11}{15}+\frac{24}{27}-\frac{2}{27}\)

\(H=\left(\frac{4}{15}+\frac{11}{15}\right)+\left(\frac{-23}{28}+\frac{23}{28}\right)+\left(\frac{24}{27}-\frac{2}{27}\right)\)

\(H=1+0+\frac{22}{27}\)

\(H=\frac{49}{27}\)

4 tháng 10 2021

yutyugubhujyikiu

10 tháng 1 2017

\(\frac{27}{23}\)\(\frac{5}{15}\)\(\frac{3}{7}\)-\(\frac{4}{23}\)\(\frac{12}{9}\)\(\frac{27}{23}\)\(\frac{1}{3}\)\(\frac{3}{7}\)-\(\frac{4}{23}\)\(\frac{4}{3}\)

= (\(\frac{27}{23}\)\(\frac{4}{23}\)) + (\(\frac{1}{3}\)\(\frac{4}{3}\)) + \(\frac{3}{7}\)

= 1+ (-1) + \(\frac{3}{7}\)\(\frac{3}{7}\)

22 tháng 4 2021

Use calculator please

21 tháng 10 2016

a,15^8*9^7/27^7*25^4

=3^8*5^8*3^14/3^21*5^8

=3^22*5^8/3^21*5^8

=3

b,9^3/(3^4-3^3)^2

=3^6/3^8-3^6

=3^6/3^6*(3^2-1)

=3^6/3^6*8

=1/8

c,(1/2-2/3+3/4-2/5):x=11/30

=> 11/60:x=11/30

=> x=11/60:11/30

=> x=1/2

d,-3/4*x+0,7*x=1,25:1/8

=> x*(-3/4+0,7)=10

=> x*(-1/20)=10

=> x=10:(-1/20)=200

Mình làm tắt lắm mong bạn thông cảm.

30 tháng 6 2021

a, \(-\dfrac{8}{18}-\dfrac{15}{27}=-\dfrac{4}{9}-\dfrac{5}{9}=\dfrac{-4-5}{9}=-\dfrac{9}{9}=-1\)

\(b,\Leftrightarrow x=\dfrac{3}{4}-\dfrac{1}{3}=\dfrac{9}{12}-\dfrac{4}{12}=\dfrac{5}{12}\)

Vậy ...

30 tháng 6 2021

\(-\dfrac{8}{18}-\dfrac{15}{27}=-1\)

\(x+\dfrac{1}{3}=\dfrac{3}{4}\)

\(x=\dfrac{3}{4}-\dfrac{1}{3}\)

\(x=\dfrac{9}{12}-\dfrac{4}{12}\)

\(x=\dfrac{5}{12}\)

20 tháng 5 2017

a: ~12.58

b: 10

c:-1

d:55/4

20 tháng 3 2018

dkr68

4 tháng 1 2022

\(\dfrac{45^{10}\cdot5^{20}}{75^{15}}=\dfrac{\left(3^2\cdot5\right)^{10}\cdot5^{20}}{\left(3\cdot5^2\right)^{15}}=\dfrac{3^{20}\cdot5^{10}\cdot5^{20}}{3^{15}\cdot5^{30}}=3^5=243\\ \dfrac{6^6+6^3+3^3+3^6}{-73}=\dfrac{46656+216+27+729}{-73}=-\dfrac{47628}{73}\\ \dfrac{27^7+3^{15}}{9^9-27}=\dfrac{\left(3^3\right)^7+3^{15}}{\left(3^2\right)^9-3^3}=\dfrac{3^{21}+3^{15}}{3^{18}-3^3}=\dfrac{3^{15}\left(3^6+1\right)}{3^3\left(3^{15}-1\right)}=\dfrac{3^5\cdot730}{3^{15}-1}\\ \dfrac{8^{20}+4^{20}}{4^{25}+64^5}=\dfrac{\left(2^3\right)^{20}+\left(2^2\right)^{20}}{\left(2^2\right)^{25}+\left(2^6\right)^5}=\dfrac{2^{60}+2^{40}}{2^{50}+2^{30}}=\dfrac{2^{40}\left(2^{20}+1\right)}{2^{30}\left(2^{20}+1\right)}=2^{10}=1024\)

3 tháng 7 2023

\(\dfrac{4}{15}-\dfrac{23}{28}-\left(-\dfrac{23}{28}+-\dfrac{11}{5}-\dfrac{29}{27}\right)-\dfrac{2}{27}\)

\(=\dfrac{4}{15}-\dfrac{23}{28}+\dfrac{23}{28}+\dfrac{11}{5}+\dfrac{29}{27}-\dfrac{2}{27}\)

\(=\left(\dfrac{4}{15}+\dfrac{11}{5}\right)+\left(-\dfrac{23}{28}+\dfrac{23}{28}\right)+\left(\dfrac{29}{27}-\dfrac{2}{27}\right)\)

\(=\left(\dfrac{4}{15}+\dfrac{33}{15}\right)+0+1\)

\(=\dfrac{37}{15}+1\)

\(=\dfrac{52}{15}\)

3 tháng 7 2023

Chỗ -11/5 em đem dấu - để trên tử nhé Phong