\(\Leftrightarrow\)\(\left(\frac{2}{3}+\frac{x}{5}\right)\)\(\times30-26=54\)

\(\Leftrightarrow20+6x\)\(-26=54\)

\(\Leftrightarrow6x=54+26-20\)

\(\Leftrightarrow6x=60\)

\(\Leftrightarrow x=10\)

Học tốt!

\(\left(\frac{4}{5}:\frac{6}{5}+\frac{1}{5}:\frac{1}{x}\right)\cdot30-26=54\)

\(\left(\frac{4}{5}\cdot\frac{5}{6}+\frac{1}{5}\cdot x\right)\cdot30=54+26\)

\(\left(\frac{2}{3}+\frac{x}{5}\right)\cdot30=80\)

\(\frac{2}{3}+\frac{x}{5}=80:30\)

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

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

\(\frac{x}{5}=2\)

\(x=10\)

\(\left(\dfrac{4}{5}:\dfrac{6}{5}+\dfrac{1}{5}:\dfrac{1}{x}\right)\times30-26=54\)

\(\left(\dfrac{4}{5}\times\dfrac{5}{6}+\dfrac{1}{5}\times x\right)\times30=54+26\)

\(\left(\dfrac{4}{6}+\dfrac{1}{5}\times x\right)\times30=80\)

\(\dfrac{4}{6}+\dfrac{1}{5}\times x=\dfrac{8}{3}\)

\(\dfrac{1}{5}\times x=\dfrac{8}{3}-\dfrac{4}{6}\)

\(\dfrac{1}{5}\times x=2\)

\(x=2:\dfrac{1}{5}\)

\(x=2\times5\)

\(x=10\)

`( 4/5 : 6/5 + 1/5 : 1/x ) xx 30 = 26 = 54`

Hai dấu `=` là sao nhỉ ?

x ở đâu thế bạn

$\textbf{1a)}$

$(1+3+5+\cdots+999)(1\cdot65\cdot101\cdot37)$

$=(500^2)(65\cdot37\cdot101)$

$=250000\cdot2405\cdot101$

$=250000\cdot242905$

$=60726250000.$

$\textbf{1b)}$

$2+4+6+\cdots+2014$

$=2(1+2+\cdots+1007)$

$=2\cdot\dfrac{1007\cdot1008}{2}$

$=1007\cdot1008$

$=1015056.$

\(\left(\frac{4}{5}:\frac{6}{5}+\frac{1}{5}:\frac{1}{x}\right)\cdot30-26=54\)

\(\left(\frac{2}{3}+\frac{x}{5}\right)\cdot30=54\cdot26\)

\(\left(\frac{2}{3}+\frac{x}{5}\right)\cdot30=1404\)

\(\frac{2}{3}+\frac{x}{5}=1404:30\)

\(\frac{2}{3}+\frac{x}{5}=\frac{234}{5}\)

\(\frac{x}{5}=\frac{234}{5}-\frac{2}{3}\)

\(\frac{x}{5}=\frac{692}{15}\)

\(x=\frac{692}{15}\cdot5\)

\(x=\frac{692}{3}\)

\(\left(\frac{4}{5}:\frac{6}{5}+\frac{1}{5}:\frac{1}{x}\right)\times30-26=54\)

\(\Leftrightarrow\left(\frac{4}{5}\times\frac{5}{6}+\frac{1}{5}\times x\right)\times30=80\)

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

\(\Leftrightarrow\frac{1}{5}\times x=2\)

\(\Leftrightarrow x=2:\frac{1}{5}\)

\(\Leftrightarrow x=2\times5\)

\(\Leftrightarrow x=10\)

Vậy x = 10. 

Matcha