b) song song :c ss d,d ss e ,e ss c

c)các bộ ba điểm thẳng hàng:ABC;DEF

d)điểm B nằm giữa hai điểm A và C

A=B nha

TL

2x - \(\frac{3}{4}\) = \(\frac{55}{20}\)

2x                      = \(\frac{55}{20}+\frac{3}{4}\)

2x                      = \(\frac{7}{2}\)

 x                       = \(\frac{7}{2}:2\)

x                       = \(\frac{7}{4}\)

HT

2x - 3/4 = 55/60

        2x = 55/60 + 3/4

        2x = 5/3

          x = 5/3 : 2

          x = 5/6

Chúc bạn học tốt.

😁😁😁

\(\dfrac{2}{5}+x+20\%=\dfrac{69}{10}\\ \Rightarrow\dfrac{2}{5}+x+\dfrac{1}{5}=\dfrac{69}{10}\\ \Rightarrow\dfrac{3}{5}+x=\dfrac{69}{10}\\ \Rightarrow x=\dfrac{69}{10}-\dfrac{3}{5}\\ \Rightarrow x=\dfrac{63}{10}\)

2/5+x= 69/10-20%

2/5+x= 67/10

x= 67/10-2/5

x= 63/10

TL

X - \(\frac{1}{4} = \frac{7}{2} x \frac{-3}{5}\)

X - \(\frac{1}{4}=\frac{-21}{10}\)

              X       =\(\frac{-21}{10} + /frac{1}{4}\)

             X       =\frac{-37}{20}\)

nha bn

HT

TL

\(\frac{x+5}{36} = \frac{4}{x+5}\)

=> (x+5)(x+5)=36x4

=> (x+5)^2=144

=>(x+5)^2=12^2 hoặc (x+5)=-12^2

=>x+5=12                  x+5=-12

=>   x=12-5                    x=-12-5

=>  x=7                          x=-17

HT

\(\dfrac{x+5}{36}=\dfrac{4}{x+5}\\ \Rightarrow\left(x+5\right)^2=144\\ \Rightarrow\left[{}\begin{matrix}x+5=12\\x+5=-12\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=7\\x=-17\end{matrix}\right.\)

= 7/20 nha mik cx ko bt 

\(x\left(5-x\right)^{2018}-\left(5-x\right)^{2019}=0\)

\(\Leftrightarrow\left(5-x\right)^{2018}\left[x-\left(5-x\right)\right]=0\Leftrightarrow\left(5-x\right)^{2018}\left(2x-5\right)=0\Leftrightarrow x=5;x=\dfrac{5}{2}\)