K
Khách

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

15 tháng 12 2022

  \(\dfrac{1}{3}\)x 2\(\dfrac{1}{5}\) + \(\dfrac{1}{3}\) x ( -0,8)

=  \(\dfrac{1}{3}\) x ( 2\(\dfrac{1}{5}\) - 0,8)

\(\dfrac{1}{3}\) x ( \(\dfrac{11}{5}\) - \(\dfrac{4}{5}\))

\(\dfrac{1}{3}\) x \(\dfrac{7}{5}\)

\(\dfrac{7}{15}\)

24 tháng 8 2023

a) \(3\times\dfrac{4}{11}=\dfrac{3\times4}{11}=\dfrac{12}{11}\)

b) \(1\times\dfrac{5}{4}=\dfrac{1\times5}{4}=\dfrac{5}{4}\)

c) \(0\times\dfrac{2}{5}=\dfrac{0\times2}{5}=\dfrac{0}{5}=0\)

a: \(=\dfrac{3\cdot4}{11}=\dfrac{12}{11}\)

b: \(=\dfrac{1\cdot5}{4}=\dfrac{5}{4}\)

c: \(=\dfrac{0\cdot2}{5}=0\)

11 tháng 3 2023

help me ạ!

11 tháng 3 2023

9/5+2/5x4/6=31/15

a: Số số hạng là \(\dfrac{2018-2}{2}+1=1009\left(số\right)\)

Tổng là: \(\dfrac{2018+2}{2}\cdot1009=1009\cdot1010=1019090\)

b: \(10S=10^2+10^3+...+10^{101}\)

\(\Rightarrow9S=10^{101}-10\)

hay \(S=\dfrac{10^{101}-10}{9}\)

c: \(5S=1+\dfrac{1}{5}+...+\dfrac{1}{5^{99}}\)

\(\Leftrightarrow4S=1-\dfrac{1}{5^{100}}\)

hay \(S=\dfrac{1}{4}\left(1-\dfrac{1}{5^{100}}\right)\)

14 tháng 5 2022

Giúp mik zới, mik đang cần gấp

14 tháng 5 2022

bài 1 : rút gọn

bài 2 : tìm x

 

9 tháng 3 2017

a,

\(\dfrac{\left(3^3\right)^{15}.5^3.\left(2^3\right)^4}{\left(5^2\right)^2.\left(3^4\right)^{11}.2^{11}}=\dfrac{3^{45}.5^3.2^{12}}{5^4.3^{44}.2^{11}}=\dfrac{6}{5}\)

b, \(\left(-\dfrac{14}{25}\right)^2.\dfrac{125}{49}+\left(-3\dfrac{11}{36}\right).2\dfrac{2}{17}=\dfrac{4}{5}.\left(-7\right)=-\dfrac{28}{5}\)

c, \(\dfrac{1}{3}-2.1=-\dfrac{5}{3}\)

17 tháng 9 2023

`4 1/5 xx 2 1/4`

`= 21/5 xx 9/4`

`= 189/20`

__

`4 1/5 : 2 1/4`

`= 21/5 : 9/4`

`= 21/5 xx 4/9`

`=84/45`

`=28/15`

__

`3 3/5 xx 1 2/3`

`= 18/5 xx 5/3`

`= 90/15`

`=6`

__

`3 3/5 : 1 2/3`

`= 18/5 : 5/3`

`= 18/5 xx 3/5`

`=54/25`

\(4\dfrac{1}{5}\times2\dfrac{1}{4}\\ =\dfrac{21}{5}\times\dfrac{9}{4}\\ =\dfrac{21\times9}{5\times4}\\ =\dfrac{189}{20}\)

 

\(3\dfrac{3}{5}\times1\dfrac{2}{3}\\ =\dfrac{18}{5}\times\dfrac{5}{3}\\ =\dfrac{18\times5}{5\times3}\\ =\dfrac{90}{15}\\ =6\)

 

\(4\dfrac{1}{5}:2\dfrac{1}{4}\\ =\dfrac{21}{5}:\dfrac{9}{4}\\ =\dfrac{21}{5}\times\dfrac{4}{9}\\ =\dfrac{21\times4}{5\times9}\\ =\dfrac{84}{45}\\ =\dfrac{28}{15}\)

 

\(3\dfrac{3}{5}:1\dfrac{2}{3}\\ =\dfrac{18}{5}:\dfrac{5}{3}\\ =\dfrac{18}{5}\times\dfrac{3}{5}\\ =\dfrac{18\times3}{5\times5}\\ =\dfrac{54}{25}\)

26 tháng 7 2017

a, \(4\times\left(-\dfrac{1}{2}\right)^3-2\times\left(-\dfrac{1}{2}\right)^2+3\times\left(-\dfrac{1}{2}\right)+1\)

\(=\left(-\dfrac{1}{2}\right)\left[\left(4\times-\dfrac{1}{2}\right)-\left(2\times-\dfrac{1}{2}\right)+3\right]+1\)

\(=\left(-\dfrac{1}{2}\right)\left(-2+1+3\right)+1\)

\(=\left(-\dfrac{1}{2}\right)2+1\)

\(=-1+1\)

\(=0\)

@Trịnh Thị Thảo Nhi

29 tháng 4 2018

a, 4×(−12)3−2×(−12)2+3×(−12)+14×(−12)3−2×(−12)2+3×(−12)+1

=(−12)[(4×−12)−(2×−12)+3]+1=(−12)[(4×−12)−(2×−12)+3]+1

=(−12)(−2+1+3)+1=(−12)(−2+1+3)+1

=(−12)2+1=(−12)2+1

=−1+1=−1+1

=0=0

a: \(=\left(\dfrac{17}{10}+\dfrac{70}{10}-\dfrac{87}{10}\right):\left(\dfrac{23}{4}-\dfrac{11}{4}+\dfrac{9}{25}\right)\cdot\left(12,98\cdot0,25\right)+12,5\)

\(=0:\left(3+\dfrac{9}{25}\right)\cdot\left(12,98+0,25\right)+12,5\)

=12,5

b: \(=\dfrac{13}{12}\cdot\dfrac{27}{5}\cdot2\cdot\dfrac{34}{9}\cdot2\cdot\dfrac{2}{17}\)

\(=\dfrac{13}{12}\cdot2\cdot\dfrac{27}{5}\cdot\dfrac{34}{9}\cdot\dfrac{4}{17}\)

\(=\dfrac{13}{6}\cdot\dfrac{27}{5}\cdot\dfrac{8}{9}=\dfrac{8}{6}\cdot3\cdot\dfrac{13}{5}=4\cdot\dfrac{13}{5}=\dfrac{52}{5}\)

HQ
Hà Quang Minh
Giáo viên
27 tháng 11 2023

a) $\frac{2}{5} \times \frac{3}{8} \times \frac{3}{4} = \frac{{2 \times 3 \times 3}}{{5 \times 8 \times 4}} = \frac{{18}}{{160}} = \frac{9}{{80}}$

b) $\frac{1}{3} \times \frac{1}{6} \times \frac{1}{9} = \frac{{1 \times 1 \times 1}}{{3 \times 6 \times 9}} = \frac{1}{{162}}$

c) $\frac{3}{4}:\frac{1}{5}:\frac{7}{8} = \frac{3}{4} \times \frac{5}{1} \times \frac{8}{7} = \frac{{3 \times 5 \times 8}}{{4 \times 1 \times 7}} = \frac{{120}}{{28}} = \frac{{30}}{7}$

d) $\frac{3}{5}:\frac{1}{5}:\frac{3}{8} = \frac{3}{5} \times \frac{5}{1} \times \frac{8}{3} = \frac{{3 \times 5 \times 8}}{{5 \times 1 \times 3}} = 8$