a) \(\dfrac{6^3+3.6^2+3^3}{-13}\)b) \(\dfrac{5^4.20^4}{24^5.4^5}\)

TT

Tiểu Thư Họ Đỗ

25 tháng 7 2017

Tính

\(a.\left(\dfrac{3}{7}+\dfrac{1}{2}\right)^2;b.\left(\dfrac{3}{4}-\dfrac{5}{6}\right)^2;c.\dfrac{5^4.20^4}{25^5.4^5};c.\left(\dfrac{-10}{3}\right)^5.\left(\dfrac{-6}{5}\right)^4\)

#Toán lớp 7

1

NT

Nguyễn Thanh Hằng

25 tháng 7 2017

a) \(\left(\dfrac{3}{7}+\dfrac{1}{2}\right)^2=\left(\dfrac{13}{14}\right)^2=\dfrac{169}{196}\)

b) \(\left(\dfrac{3}{4}-\dfrac{5}{6}\right)^2=\left(\dfrac{-1}{12}\right)^2=\dfrac{1}{144}\)

c) \(\dfrac{5^4.20^4}{25^5.4^5}=\dfrac{\left(5.20\right)^4}{\left(25.4\right)^5}=\dfrac{100^4}{100^5}=\dfrac{1}{100}\)

d) \(\left(\dfrac{-10}{3}\right)^5.\left(\dfrac{-6}{5}\right)^4=\dfrac{-10^5}{3^5}.\dfrac{-6^4}{5^4}=\dfrac{-\left(2.5\right)^5.\left(3.2\right)^4}{3^5.5^4}=\dfrac{-29.5}{3}=-853\dfrac{1}{3}\)

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LH

Lan Hương

1 tháng 10 2023 - olm

\(\dfrac{4^5.9^4}{8^3.27^3}\);\(\dfrac{4^{20}.3^{35}}{2^{37}.27^{12}}\)\(;\dfrac{5^4.20^4}{25^5.4^5};\dfrac{2^{15}.9^4}{6^6.8^3}\)

#Toán lớp 7

1

ND

Nguyễn Đăng Nhân

1 tháng 10 2023

\(\dfrac{4^5\cdot9^4}{8^3\cdot27^3}=\dfrac{\left(2^2\right)^5\cdot\left(3^2\right)^4}{\left(2^3\right)^3\cdot\left(3^3\right)^3}=\dfrac{2^{10}\cdot3^8}{2^9\cdot3^9}=\dfrac{2}{3}\)

\(\dfrac{4^{20}\cdot3^{35}}{2^{37}\cdot27^{12}}=\dfrac{\left(2^2\right)^{20}\cdot3^{35}}{2^{37}\cdot\left(3^3\right)^{12}}=\dfrac{2^{40}\cdot3^{35}}{2^{37}\cdot3^{36}}=\dfrac{2^3}{3}\)

\(\dfrac{5^4\cdot20^4}{25^5\cdot4^5}=\dfrac{5^4\cdot5^4\cdot4^4}{5^5\cdot5^5\cdot4^5}=\dfrac{1}{5^2\cdot4}=\dfrac{1}{100}\)

\(\dfrac{2^{15}\cdot9^4}{6^6\cdot8^3}=\dfrac{2^{15}\cdot\left(3^2\right)^4}{2^6\cdot3^6\cdot\left(2^3\right)^3}=\dfrac{2^{15}\cdot3^8}{2^6\cdot3^6\cdot2^9}=3^2\)

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R

rinjin

8 tháng 10 2023

tính
a) A = \(\dfrac{6^3+3.6^2+3^3}{-13}\)
b) B =\(\dfrac{2.8^4.27^2+4.6^9}{2^3.6^7+2^7.40.9^4}\)
c) C=\(\dfrac{5.4^{15}.9^9-4.3^{20}.8^9}{5.2^{16}.6^{19}-7.2^{29}.27^6}\)

#Toán lớp 7

1

NL

Nguyễn Lê Phước Thịnh

8 tháng 10 2023

a: \(A=\dfrac{3^3\cdot2^3+3^3\cdot2^2+3^3\cdot1}{-13}=\dfrac{27\left(2^3+2^2+1\right)}{-13}=-27\)

b: \(B=\dfrac{2\cdot2^{12}\cdot3^6+2^{11}\cdot3^9}{2^3\cdot2^7\cdot3^7+2^7\cdot2^3\cdot5\cdot3^8}\)

\(=\dfrac{2^{13}\cdot3^6+2^{11}\cdot3^9}{2^{10}\cdot3^7+2^{10}\cdot5\cdot3^8}\)

\(=\dfrac{2^{11}\cdot3^6\left(2^2+3^3\right)}{2^{10}\cdot3^7\left(1+5\cdot3\right)}=\dfrac{2}{3}\cdot\dfrac{4+27}{1+15}=\dfrac{2}{3}\cdot\dfrac{31}{16}=\dfrac{31}{24}\)

c: \(C=\dfrac{5\cdot2^{30}\cdot3^{18}-2^{29}\cdot3^{20}}{5\cdot2^{35}\cdot3^{19}-7\cdot2^{29}\cdot3^{18}}\)

\(=\dfrac{2^{29}\cdot3^{18}\left(5\cdot2-3^2\right)}{2^{29}\cdot3^{18}\left(5\cdot2^6-7\right)}=\dfrac{10-9}{5\cdot64-7}=\dfrac{1}{313}\)

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NN

Núi non tình yêu thuần khiết

15 tháng 12 2017

Tính nhanh nếu có thể:

a) \(\dfrac{15}{12}+\dfrac{5}{13}-\dfrac{3}{12}-\dfrac{18}{13}\)

b) \(\dfrac{5^4.20^4}{25^5.4^5}\)

c) \(\dfrac{8^{10}+4^{10}}{8^4+4^{11}}\)

#Toán lớp 7

1

DV

Đời về cơ bản là buồn... cười!!!

15 tháng 12 2017

a) \(\dfrac{15}{12}+\dfrac{5}{13}-\dfrac{3}{12}-\dfrac{18}{13}\)

\(=\left(\dfrac{15}{12}-\dfrac{3}{12}\right)+\left(\dfrac{5}{13}-\dfrac{18}{13}\right)\)

\(=\dfrac{12}{12}+\dfrac{-13}{13}\)

\(=1-1\)

\(=0\)

b) \(\dfrac{5^4\cdot20^4}{25^5\cdot4^5}\)

\(=\dfrac{100^4}{100^5}\)

\(=\dfrac{1}{100}\)

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CC

Công chúa thủy tề

15 tháng 12 2017 - olm

Tính nhanh nếu có thể:

a) \(\dfrac{15}{12}+\dfrac{5}{13}-\dfrac{3}{12}-\dfrac{18}{13}\)

b) \(\dfrac{5^4.20^4}{25^5.4^5}\)

c) \(\dfrac{8^{10}+4^{10}}{8^4+4^{11}}\)

#Toán lớp 7

1

TT

Thanh Tùng DZ

15 tháng 12 2017

a) \(\frac{15}{12}+\frac{5}{13}-\frac{3}{12}-\frac{18}{13}\)

\(=\left(\frac{15}{12}-\frac{3}{12}\right)+\left(\frac{5}{13}-\frac{18}{13}\right)\)

\(=1+\left(-1\right)\)

\(=0\)

b) \(\frac{5^4.20^4}{25^5.4^5}=\frac{\left(20.5\right)^4}{\left(25.4\right)^5}=\frac{100^4}{100^5}=\frac{1}{100}\)

c) \(\frac{8^{10}+4^{10}}{8^4+4^{11}}=\frac{\left(2^3\right)^{10}+\left(2^2\right)^{10}}{\left(2^3\right)^4+\left(2^2\right)^{11}}=\frac{2^{30}+2^{20}}{2^{12}+2^{22}}=\frac{2^{12}.\left(2^{18}+2^8\right)}{2^{12}.\left(1+2^{10}\right)}=\frac{2^{18}+2^8}{1+2^{10}}=256\)

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SG

Sách Giáo Khoa

18 tháng 4 2017

Tính :

a) \(\left(\dfrac{3}{7}+\dfrac{1}{2}\right)^2\)

b) \(\left(\dfrac{3}{4}-\dfrac{5}{6}\right)^2\)

c) \(\dfrac{5^4.20^4}{25^5.4^5}\)

d) \(\left(\dfrac{-10}{3}\right)^5.\left(\dfrac{-6}{5}\right)^4\)

#Toán lớp 7

2

LH

Lưu Hạ Vy

18 tháng 4 2017

a) =

b) =

c) =

d) = .

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TN

Thạch Nguyễn

15 tháng 6 2017

a) \(\left(\dfrac{3}{7}+\dfrac{1}{2}\right)^2=\left(\dfrac{6}{14}+\dfrac{7}{17}\right)^2=\left(\dfrac{13}{12}\right)^2=\dfrac{13^2}{12^2}=\dfrac{169}{144}\)

b)\(\left(\dfrac{3}{4}-\dfrac{5}{6}\right)^2=\left(\dfrac{9}{12}-\dfrac{10}{12}\right)^2=\left(\dfrac{-1}{12}\right)^2=\dfrac{\left(-1\right)^2}{12^2}=\dfrac{1}{144}\)

c)\(\dfrac{5^4.20^4}{25^5.4^5}=\dfrac{5^4.5^4.2^8}{5^{10}.2^{10}}=\dfrac{5^8.2^8}{5^8.5^2.2^8.2^2}=\dfrac{1}{5^2.2^2}=\dfrac{1}{25.4}=\dfrac{1}{100}\)

d)\(\left(\dfrac{-10}{3}\right)^5.\left(\dfrac{-6}{5}\right)^4=\dfrac{\left(-10\right)^5.\left(-6\right)^4}{3^5.5^4}=\dfrac{\left(-2\right)^5.5^5.2^4.3^4}{3^4.3.5^4}=\dfrac{\left(-2\right)^5.5.5^42^4}{3.5^4}=\dfrac{\left(-2\right)^5.5.2^4}{3}=\dfrac{-2560}{3}=-853\dfrac{1}{3}\)

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NT

Nguyễn Thị Huyền Trang

26 tháng 6 2017

Tính

a) (\(\dfrac{3}{7}\)+\(\dfrac{1}{2}\))² b) (\(\dfrac{3}{4}\)-\(\dfrac{5}{6}\))² c) \(\dfrac{5^4.20^4}{25^5.4^5}\) d) (\(\dfrac{-10}{3}\))⁵.(\(\dfrac{-6}{5}\))⁴

#Toán lớp 7

1

DH

Đức Hiếu

26 tháng 6 2017

a, \(\left(\dfrac{3}{7}+\dfrac{1}{2}\right)^2=\left(\dfrac{3}{7}\right)^2+2.\dfrac{3}{7}.\dfrac{1}{2}+\left(\dfrac{1}{2}\right)^2\)

\(=\dfrac{9}{49}+\dfrac{3}{7}+\dfrac{1}{4}=\dfrac{169}{196}\)

b, \(\left(\dfrac{3}{4}-\dfrac{5}{6}\right)^2=\left(\dfrac{3}{4}\right)^2-2.\dfrac{3}{4}.\dfrac{5}{6}+\left(\dfrac{5}{6}\right)^2\)

\(=\dfrac{9}{16}-\dfrac{5}{4}+\dfrac{25}{36}=\dfrac{1}{144}\)

c, \(\dfrac{5^4.20^4}{25^5.4^5}=\dfrac{5^4.5^4.4^4}{5^{10}.4^5}=\dfrac{1}{5^2.4}=\dfrac{1}{100}\)

d, \(\left(\dfrac{-10}{3}\right)^5.\left(\dfrac{-6}{5}\right)^4=\dfrac{\left(-10\right)^5}{3^5}.\dfrac{6^4}{5^4}\)

\(=\dfrac{5^5.\left(-2\right)^5.2^4.3^4}{3^5.5^4}=\dfrac{-\left(5.2^9\right)}{3}=\dfrac{-2560}{3}\)

Chúc bạn học tốt!!!

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TH

Thuyet Hoang

2 tháng 10 2021

BÀI 2 TÍNH :

A = \(\dfrac{6^3+3.6^2+3^3}{13}\)

B = \(\dfrac{4^6.9^5+6^9.120}{8^4-3^{12}.6^{11}}\)

#Toán lớp 7

2

TH

Thuyet Hoang

2 tháng 10 2021

MN ƠI GIÚP MÌNH VỚI MÌNH CẦN GẤP

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NL

Nguyễn Lê Phước Thịnh

2 tháng 10 2021

\(A=\dfrac{6^3+3\cdot6^2+3^3}{13}\)

\(=\dfrac{3^3\cdot8+3^3\cdot4+3^3}{13}\)

=27

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NT

Nguyễn Thị Hoài An

5 tháng 7 2016

Bài 1) Rút gọn biểu thức

a) \(\frac{2^7.9^3}{6^5.8^2}\)

b) \(\frac{6^3+3.6^2+3^3}{-13}\)

c) \(\frac{5^4.20^4}{25^5.4^5}\)

d)(\(\frac{5^4-5^3}{125^4}\) )

#Toán lớp 7

4

PA

Phương An

5 tháng 7 2016

a.

\(\frac{2^7\times9^3}{6^5\times8^2}=\frac{2^7\times\left(3^2\right)^3}{\left(2\times3\right)^5\times\left(2^3\right)^2}=\frac{2^7\times3^6}{2^5\times3^5\times2^6}=\frac{3}{2^4}=\frac{3}{16}\)

b.

\(\frac{6^3+3\times6^2+3^3}{-13}=\frac{\left(2\times3\right)^3+3\times\left(3\times2\right)^2+3^3}{-13}=\frac{2^3\times3^3+3\times3^2\times2^2+3^3}{-13}=\frac{8\times3^3+3^3\times4+3^3}{-13}\)\(=\frac{3^3\times\left(8+4+1\right)}{-13}=\frac{27\times13}{-13}=-27\)

c.

\(\frac{5^4\times20^4}{25^5\times4^5}=\frac{\left(5\times20\right)^4}{\left(25\times4\right)^5}=\frac{100^4}{100^5}=\frac{1}{100}\)

d.

\(\left(\frac{5^4-5^3}{125^4}\right)=\frac{5^3\times\left(5-1\right)}{\left(5^3\right)^4}=\frac{5^3\times4}{5^{12}}=\frac{4}{5^9}\)

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NN

Nobi Nobita

5 tháng 7 2016

a)\(\frac{2^7.9^3}{6^5.8^2}=\frac{2^7.\left(3^2\right)^3}{2^5.3^5.\left(2^3\right)^2}=\frac{2^7.3^6}{2^5.3^5.2^6}=\frac{3}{2^4}\)

b)\(\frac{6^3+3.6^2+3^3}{-13}=\frac{6.6^2+3.6^2+3^3}{-13}=\frac{6^2.\left(6+3\right)+3^3}{-13}=\frac{6^2.9+3^3}{-13}=\frac{6^2.3^2+3.3^2}{-13}=\frac{3^2.\left(6^2+3\right)}{-13}=\frac{3^2.39}{-13}=3^2.\left(-3\right)=-27\)

c)\(\frac{5^4.20^4}{25^5.4^5}=\frac{100^4}{100^5}=\frac{1}{100}\)

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