K
Khách

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

3 tháng 7 2018

3 5 : − 1 1 15 − 1 6 + 3 5 : − 1 3 − 1 1 15 = 3 5 : − 16 15 − 1 6 + 3 5 : − 1 3 − 16 15 = 3 5 : − 37 30 + 3 5 : 7 5 = 3 5 . − 30 37 + 3 5 . 5 7 = − 18 37 + 3 7 = − 12 259

a: \(=\dfrac{5}{7}\left(\dfrac{5}{11}+\dfrac{2}{11}-\dfrac{14}{11}\right)=\dfrac{5}{7}\cdot\dfrac{-7}{11}=-\dfrac{5}{11}\)

b: \(=\dfrac{12}{7}\left(19+\dfrac{5}{8}-15-\dfrac{1}{4}\right)=\dfrac{12}{7}\cdot\left(4+\dfrac{3}{8}\right)\)

\(=\dfrac{12}{7}\cdot\dfrac{35}{8}=\dfrac{3}{2}\cdot5=\dfrac{15}{2}\)

c: \(=\dfrac{2}{15}-\dfrac{2}{15}\cdot5+\dfrac{3}{15}=\dfrac{2}{15}\cdot\left(-4\right)+\dfrac{3}{15}=\dfrac{-8+3}{15}=\dfrac{-5}{15}=-\dfrac{1}{3}\)

d: \(=\dfrac{4}{9}\left(19+\dfrac{1}{3}-39-\dfrac{1}{3}\right)=\dfrac{4}{9}\cdot\left(-20\right)=-\dfrac{80}{9}\)

Bài 1: 

c) \(\dfrac{1}{y}\sqrt{19y}=\sqrt{19y\cdot\dfrac{1}{y^2}}=\sqrt{\dfrac{19}{y}}\)

d) \(\dfrac{1}{3y}\cdot\sqrt{\dfrac{27}{y^2}}\cdot y=\sqrt{\dfrac{1}{9}\cdot\dfrac{27}{y^2}}=\sqrt{\dfrac{3}{y^2}}\)

Bài 3: 

a) Ta có: \(\left(\dfrac{2}{\sqrt{3}-1}+\dfrac{3}{\sqrt{3}-2}+\dfrac{15}{3-\sqrt{3}}\right)\cdot\dfrac{1}{\sqrt{3}+5}\)

\(=\left(\dfrac{2\left(\sqrt{3}+1\right)}{2}-\dfrac{3\left(2+\sqrt{3}\right)}{1}+\dfrac{15\left(3+\sqrt{3}\right)}{6}\right)\cdot\dfrac{1}{\sqrt{3}+5}\)

\(=\left(\sqrt{3}+1-2-\sqrt{3}+\dfrac{5\left(3+\sqrt{3}\right)}{2}\right)\cdot\dfrac{1}{\sqrt{3}+5}\)

\(=\left(-1+\dfrac{5\left(3+\sqrt{3}\right)}{2}\right)\cdot\dfrac{1}{5+\sqrt{3}}\)

\(=\dfrac{-2+15+5\sqrt{3}}{2\left(5+\sqrt{3}\right)}\)

\(=\dfrac{13+5\sqrt{3}}{10+2\sqrt{3}}\)

a: \(=\dfrac{4}{9}\left(4+\dfrac{1}{3}+13+\dfrac{2}{3}\right)=\dfrac{4}{9}\cdot18=8\)

b: \(=\dfrac{3}{8}\left(5+\dfrac{1}{4}+10+\dfrac{3}{4}\right)=\dfrac{3}{8}\cdot16=6\)

c: \(=\dfrac{-2}{7}\left(6+\dfrac{1}{5}+14+\dfrac{4}{5}\right)=\dfrac{-2}{7}\cdot21=-6\)

5 tháng 3 2023

giúp nhanh ạ, mình cần gấp

Bài 5:

a: =1/3+2/5

=5/15+6/15

=11/15

b: =6/21+12/21=18/21=6/7

c: =16/24+10/24

=26/24

=13/12

d: =4/12+3/12+10/12

=17/12

e: =19/24-9/24

=10/24

=5/12

f: =8/9-3/9=5/9

g: =9/3+1/3=10/3

k: =15/24+42/24+14/24

=71/24

8 tháng 10 2019

\(a,10.a^6+20a^5=10a^5\left(a+2\right)\)

\(b,5x^2-10xy+5y^2=5\left(x^2-2xy+y^2\right)=5\left(x-y\right)^2\)

\(c,3ab^3+6ab^2-18ab=3ab\left(b^2+2b-1\right)\)

\(d,15x^3y^2+10x^2y^2-20x^2y^3=5x^2y^2\left(3x+2-4y\right)\)

\(e,a^2\left(x-1\right)-b\left(1-x\right)=a^2\left(x-1\right)+b\left(x-1\right)=\left(x-1\right)\left(a^2+b\right)\)

\(f,x\left(x-5\right)-4\left(5-x\right)=x\left(x-5\right)+4\left(x-5\right)=\left(x-5\right)\left(x+4\right)\)

(mk sửa lại thứ tự là a,b,c,d,e,f nha)

chúc bn học tốt

8 tháng 10 2019

\(1,10a^6+20a^5=10a^5\left(a+10\right)\)

\(2,5x^2-10xy+5y^2=5\left(x^2-2xy+y^2\right)\)

\(=5\left(x-y\right)^2\)

\(3,3ab^3+6ab^2-18ab\)

\(=3ab\left(b^2+2b-6\right)\)

\(4,15x^3y^2+10x^2y^2-20x^2y^3\)

\(=5x^2y^2\left(3x+2-4y\right)\)

\(5,a^2\left(x-1\right)-b\left(1-x\right)\)

\(=a^2\left(x-1\right)+b\left(x-1\right)\)

\(=\left(x-1\right)\left(a^2+b\right)\)

\(6,x\left(x-5\right)-4\left(5-x\right)\)

\(=x\left(x-5\right)+4\left(x-5\right)\)

\(=\left(x+4\right)\left(x-5\right)\)

27 tháng 3

\(\left(\dfrac{5}{7}-\dfrac{7}{7}\right)-\left[0,2-\left(-\dfrac{2}{7}-\dfrac{1}{10}\right)\right]\)

=\(-\dfrac{2}{7}-\left[\dfrac{1}{5}+\dfrac{2}{7}+\dfrac{1}{10}\right]\)  

=\(-\dfrac{2}{7}-\dfrac{1}{5}-\dfrac{2}{7}-\dfrac{1}{10}\) 

=\(\left(-\dfrac{2}{7}-\dfrac{2}{7}\right)-\left(\dfrac{1}{5}+\dfrac{1}{10}\right)\) 

=\(-\dfrac{4}{7}-\left(\dfrac{2}{10}+\dfrac{1}{10}\right)\) 

=\(-\dfrac{4}{7}-\dfrac{3}{10}\) 

=\(-\dfrac{40}{70}-\dfrac{21}{70}\)

=\(-\dfrac{61}{70}\)

 

 

27 tháng 3

   (3 - \(\dfrac{1}{4}\) + \(\dfrac{2}{3}\)) - (5 - \(\dfrac{1}{3}\) - \(\dfrac{5}{6}\)) - (6 - \(\dfrac{7}{4}\) - \(\dfrac{3}{2}\))

= 3 - \(\dfrac{1}{4}\) + \(\dfrac{2}{3}\) - 5 + \(\dfrac{1}{3}\) + \(\dfrac{5}{6}\) - 6 + \(\dfrac{7}{4}\) + \(\dfrac{3}{2}\)

= (3 - 5 - 6) + ( \(\dfrac{7}{4}\) - \(\dfrac{1}{4}\)) + (\(\dfrac{2}{3}\) + \(\dfrac{1}{3}\)) +  \(\dfrac{3}{2}\) + \(\dfrac{5}{6}\)

= - 8  + \(\dfrac{3}{2}\) + 1 + \(\dfrac{3}{2}\) + \(\dfrac{5}{6}\)

= (- 8 + 1) + (\(\dfrac{3}{2}\) + \(\dfrac{3}{2}\)) + \(\dfrac{5}{6}\)

= -7 + 3 + \(\dfrac{5}{6}\)

= - 4 + \(\dfrac{5}{6}\)

\(\dfrac{-19}{6}\)

Câu 1: C

Câu 3: B

Câu 4: D

Câu 5; A

8 tháng 3 2022

Câu 1 C

Câu 3 B

Câu 4 D

Câu 5 A

22 tháng 12 2016

Bài này dễ:=\(\frac{3}{5}\)x    \(\frac{1}{\frac{-1}{15}-\frac{1}{6}}\)+\(\frac{3}{5}\)x   \(\frac{1}{\frac{-1}{3}-\frac{16}{15}}\).Tự giải tiếp nhé,nhớ chọn cho Long đẹp trai này nhé!