Bn đổi cho mk dấu { thành [ nhé

HT x2

TL
 

x=1,1

x=2,5

Đó bố 

HT

  \(|\)-4.6\(|\): \(|\)-2,3\(|\)-(-0,3)

=\(|\)-24\(|\): 2,3 + 0,3

= 24 : 2,3 + 0,3

=     80     + 0,3

=          80,3

\(a,x-\frac{1}{2}=-\frac{3}{4}\)

\(x=-\frac{3}{4}+\frac{1}{2}\)
\(x=-\frac{3}{4}+\frac{2}{4}\)

\(x=-\frac{1}{4}\)

\(b,\left|x+\frac{3}{4}\right|-5=-2\)

\(\left|x+\frac{3}{4}\right|=-2+5\)

\(\left|x+\frac{3}{4}\right|=3\)

\(\Rightarrow\hept{\begin{cases}x+\frac{3}{4}=3\Rightarrow x=\frac{9}{4}\\x+\frac{3}{4}=-3\Rightarrow x=-\frac{15}{4}\end{cases}}\)

Vậy ...

\(c,\frac{5}{6}-\frac{1}{6}\div x=\frac{3}{4}\)

\(\frac{1}{6}\div x=\frac{5}{6}-\frac{3}{4}\)

\(\frac{1}{6}\div x=\frac{10}{12}-\frac{9}{12}\)

\(\frac{1}{6}\div x=\frac{1}{12}\)

\(x=\frac{1}{6}\div\frac{1}{12}\)

\(x=\frac{1}{6}\times12\)

\(x=2\)

https://khoahoc.vietjack.com/question/661489/bieu-thuc-a-3-45-9-6-7-4-3-12-5-11-3-co-gia-tri-3-11

Ta có :

Đặt \(\frac{a}{2019}\)= \(\frac{b}{2020}\)= \(\frac{c}{2021}\)= k

=> a = 2019k; b = 2020k; c = 2021k

M = 4(a-b).(b-c) - (c-a)

M = 4(2019k- 2020k). (2020k-2021k) - (2021k - 2019k)

M = 4.(-1)k.(-1)k - 2k

M = 4k² - 2k

(Hình như mình thấy đề bạn có gì sai sai)

TL:

= -3/2

HT ^^

TL:

b//c

c

c\(\perp\) b

_HT_