a,x=4;3;2;1

b,x=2;3;4;5;6;7...

hk tốt

x =1

x=2

x=3

x=4

6*x=4*5

6*x=20

x=20:6

X=3,3

x*6=7*8

x*6=56

x=56:6

x=9,3

rtgfr

\(\frac{3}{2}x+\frac{1}{5}x=\frac{5}{8}\)

\(Xx\left(\frac{3}{2}+\frac{1}{5}\right)=\frac{5}{8}\)

\(x=\frac{5}{8}:\left(\frac{3}{2}+\frac{1}{5}\right)\)

\(x=\frac{25}{68}\)

ta có X x ( \(\frac{3}{2}+\frac{1}{5}\)) = \(\frac{5}{8}\)

          X x \(\frac{17}{10}\) = \(\frac{5}{8}\)

           X = \(\frac{5}{8}:\frac{17}{10}\)

           X = \(\frac{25}{68}\)

Lấy 24 làm mẫu số chung, giữ nguyên   \(\frac{25}{24}\) :

\(\frac{1}{2}=\frac{1\times12}{2\times12}=\frac{12}{24}\)

\(\frac{3}{8}=\frac{3\times3}{8\times3}=\frac{9}{24}\)

\(\frac{4}{6}=\frac{4\times4}{6\times4}=\frac{16}{24}\)

\(\frac{8}{4}=\frac{8\times6}{4\times6}=\frac{48}{24}\)

\(\rightarrow\)  \(\frac{48}{24};\frac{25}{24}; \frac{16}{24} ;\frac{12}{24};\frac{9}{24}\)  

\(\rightarrow\)   \(\frac{8}{4} ; \frac{25}{24} ; \frac{4}{6} ; \frac{1}{2} ; \frac{3}{8}\)

nhanh lên các mik ơi đúng em k

X + 3/8=4/3

x          =4/3-3/8

x          =23/24

X x 1/9=21/8

X         =21/8:1/9

X         =7/24

X-5/4=7/6

X       =7/6+5/4

X       =21/8

X:8/3=5

X      =5x8/3

X      =40/3

Duyệt nha!

x+ 3/8=4/3

=>x=4/3-3/8

=>x=20/24=5/6

<=>  1+\(\frac{1}{2014}\)+\(\frac{1}{x}\)=\(\frac{1}{x+1}\)+1+\(\frac{1}{2013}\)

<=>   \(\frac{1}{2014}\)+\(\frac{1}{x}\)=\(\frac{1}{x+1}\)+\(\frac{1}{2013}\)

<=>   \(\frac{1}{x}\)-\(\frac{1}{x+1}\)=\(\frac{1}{2013}\)-\(\frac{1}{2013+1}\)                  => x=2013

\(\frac{2015}{2014}+\frac{1}{x}=\frac{1}{x+1}+\frac{2014}{2013}\)

\(\Leftrightarrow\frac{2015}{2014}-1+\frac{1}{x}=\frac{1}{x+1}+\frac{2014}{2013}-1\)

\(\Leftrightarrow\frac{1}{2014}+\frac{1}{x}=\frac{1}{x+1}+\frac{1}{2013}\)

\(\Leftrightarrow\frac{x+2014}{2014x}=\frac{x+2014}{2013\left(x+1\right)}\)

\(\Leftrightarrow2014x=2013x+2013\)

\(\Leftrightarrow x=2013\)

1. n = 15;16;17;18;19;20;21;22;23;24 

2. y = 20

Bạn tự đăng câu hỏi thì bạn phải tự trả lời chứ.

k nha !