làm hộ tớ  nhé

ngu the  xcuiegudg

có ai biết bài này không xin trả lời dùm 

18 chia 2phaan 3

12 phần 25 trừ cho 14 phần 5 bằng bao nhiêu

hỏi google phay

Hỏi gg đi khó lắm

a: =>(x-2)(3x+1)-(x-2)(x+2)=0

=>(x-2)(3x+1-x-2)=0

=>(x-2)(2x-1)=0

=>x=1/2 hoặc x=2

b: =>3(x-1)+4(x+1)=6(x-1)

=>3x-3+4x+4=6x-6

=>7x+1=6x-6

=>x=-7

c: =>x(x-3)-(x+2)(x+3)+16=0

=>x^2-3x-x^2-5x-6+16=0

=>10-8x=0

=>x=5/4

Đăng 1 bài 1 thổi bn

\(\frac{5}{9}\times\frac{12}{7}=\frac{5\times12}{9\times7}=\frac{5\times4\times3}{3\times3\times7}=\frac{20}{21}\)

\(\frac{6}{5}:\frac{8}{3}=\frac{6}{5}\times\frac{8}{3}=\frac{2\times3\times8}{5\times3}=\frac{16}{5}\)

\(\frac{9}{20}\times\frac{5}{12}=\frac{3\times3\times5}{4\times5\times4\times3}=\frac{3}{16}\)

\(\frac{15}{16}:\frac{25}{24}=\frac{15}{16}\times\frac{24}{25}=\frac{3\times5\times4\times2\times3}{4\times2\times2\times5\times5}=\frac{9}{10}\)

\(14\times\frac{5}{21}=\frac{2\times7\times5}{3\times7}=\frac{10}{3}\)

\(10:\frac{5}{3}=10\times\frac{3}{5}=\frac{2\times5\times3}{5}=6\)

\(\frac{5}{3}:10=\frac{5}{3}\times\frac{1}{10}=\frac{5}{3\times2\times5}=\frac{1}{6}\)

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

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

\(x=-\frac{4}{3}\)

b)\(-\frac{3}{7}+x=\frac{5}{8}\)

\(\text{ }x=\frac{5}{8}-\left(-\frac{3}{7}\right)\)

\(x=\frac{59}{56}\)

c)\(\frac{16}{2^x}=2\)

\(2^x=\frac{16}{2}\)

\(2^x=8\)

\(\Rightarrow2^x=2^3\)

vậy x=3

(\(x\) + \(\dfrac{1}{2}\))² = \(\dfrac{1}{16}\)

\(\left[{}\begin{matrix}x+\dfrac{1}{2}=-\dfrac{1}{4}\\x+\dfrac{1}{2}=\dfrac{1}{4}\end{matrix}\right.\)

\(\left[{}\begin{matrix}x=-\dfrac{1}{4}-\dfrac{1}{2}\\x=\dfrac{1}{4}-\dfrac{1}{2}\end{matrix}\right.\)

\(\left[{}\begin{matrix}x=-\dfrac{3}{4}\\x=-\dfrac{1}{4}\end{matrix}\right.\)

Vậy \(x\) \(\in\) {- \(\dfrac{3}{4};-\dfrac{1}{4}\)}

\(x\) : (- \(\dfrac{1}{3}\))³  = - \(\dfrac{1}{3}\)

\(x\)              = (-\(\dfrac{1}{3}\)).(-\(\dfrac{1}{3}\))³

\(x\)             = \(\dfrac{1}{81}\)

Vậy \(x=\dfrac{1}{81}\)

1,

\(\frac{25}{12}+\left(\frac{-4}{12}\right)=\frac{7}{4}\)

\(\frac{-10}{8}+\frac{15}{4}=\frac{5}{2}\)

\(\frac{3}{8}+\frac{-14}{6}=\frac{-47}{24}\)

\(\frac{350}{150}+\left(\frac{-200}{360}\right)=\frac{16}{9}\)

\([\frac{5}{8}+\left(\frac{-3}{4}\right)]+\frac{15}{6}=\frac{-1}{8}+\frac{15}{6}=\frac{19}{8}\)

\(\frac{7}{3}+[\left(\frac{-5}{6}\right)+\left(\frac{-2}{3}\right)]=\frac{7}{3}+\left(\frac{-3}{2}\right)=\frac{5}{6}\)

4,

\(\frac{X+1}{5}=\frac{3}{7}\)

\(\Rightarrow\left(X-1\right).7=3.5\)

\(\Rightarrow7X-7=15\)

\(\Rightarrow7X=22\)

\(\Rightarrow X=\frac{22}{7}\)

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

\(\Rightarrow\left(X-3\right)2=1.4\)

\(\Rightarrow2X-6=4\)

\(\Rightarrow2X=10\)

\(\Rightarrow X=5\)