K
Khách

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

8 tháng 2 2017

  3 8 .19 1 3 − 3 8 .33 1 3   = 3 8 . 19 1 3 − 33 1 3   = 3 8 . − 14 = − 21 4

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

4 tháng 11 2016

a) xy + x + 8y + 8

= x.(y + 1) + 8.(y + 1)

= (y + 1).(x + 8)

b) \(x^2-x-\frac{2}{3}.x+\frac{2}{3}\)

\(=x.\left(x-1\right)-\frac{2}{3}.\left(x-1\right)\)

\(=\left(x-1\right).\left(x-\frac{2}{3}\right)\)

c) x2 - 1

= x2 + x - x - 1

= x.(x + 1) - (x + 1)

= (x + 1).(x - 1)

4 tháng 11 2016

a) (xy+x) +(8y+8)=x(y+1)+8(y+1)=(x+8)(y+1)

b) (x2-x) -(2/3x-2/3)=x(x-1)+2/3(x-1)=(x+2/3)(x-1)

c) x2-1= (x-1)(x+1)

9 tháng 12 2021

\(\dfrac{3}{8}.19\dfrac{1}{3}-\dfrac{3}{8}.33\dfrac{1}{3}=\dfrac{3}{8}\left(19\dfrac{1}{3}-33\dfrac{1}{3}\right)=-\dfrac{3}{8}.\left(-14\right)=\dfrac{21}{4}\)

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

12 tháng 9 2015

a. xy+x+8y+8

= x(y+1)+8(y+1)

= (y+1)(x+8)

b. x2-x-2/3x+2/3

= x(x-1)-2/3(x-1)

= (x-1)(x-2/3)

c. x2-1

= x2-12

= (x+1)(x-1)

6 tháng 12 2018

\(\frac{3}{8}.19\frac{1}{3}-\frac{3}{8}.33\frac{1}{3}\)

=\(\frac{3}{8}.\left(19\frac{1}{3}-33\frac{1}{3}\right)\)

=\(\frac{3}{8}.\left(19-33\right)\)

=\(\frac{3}{8}.\left(-14\right)\)

=\(\frac{3}{4}.\left(-7\right)\)=\(\frac{\left(-21\right)}{4}\)

11 tháng 8 2017

Ta có\(\dfrac{3}{8}.19\dfrac{1}{3}-\dfrac{3}{8}.33\dfrac{1}{3}=\dfrac{3}{8}\left(19\dfrac{1}{3}-33\dfrac{1}{3}\right)=\dfrac{3}{8}.\left(-14\right)=-\dfrac{21}{4}=-5,25\)

20 tháng 12 2017

\(\left(\dfrac{9}{25}-2.18\right):\left(3\dfrac{4}{5}+0,2\right)\)

=\(\left(\dfrac{9}{25}-36\right):4\)

= -35,64:4=-8,91