\(\left(x+140\right):x+260\text{=}331\)

\(\left(x+140\right):x\text{=}331-260\)

\(x:x+140:x\text{=}71\)

\(1+140:x\text{=}71\)

\(140:x\text{=}71-1\)

\(140:x\text{=}70\)

\(x\text{=}140:70\)

\(x\text{=}2\)

Trước tiên, bạn cần biết về tình chất phân số nhé:

\(\dfrac{a+b}{c}=\dfrac{a}{c}+\dfrac{b}{c}\)

Áp dụng vào bài, ta có:

\(\dfrac{\left(x+140\right)}{x}+260=331\)

\(\Rightarrow\dfrac{x}{x}+\dfrac{40}{x}+260=331\)

\(\Rightarrow1+\dfrac{40}{x}+260=331\)

\(\Rightarrow40:x=331-1-260=70\)

\(\Rightarrow x=\dfrac{40}{70}=\dfrac{4}{7}\)

\(\dfrac{42\cdot32}{12\cdot14\cdot16}\)(Dấu . là dấu nhân)
\(=\dfrac{7\cdot6\cdot8\cdot2\cdot2}{6\cdot2\cdot7\cdot2\cdot8\cdot2}\)
\(=\dfrac{1}{2}\)
 

\(\dfrac{42.32}{12.14.16}=\dfrac{1344}{2688}=\dfrac{1}{2}\)

`2424/4545=(2424:303)/(4545:303)=8/15`

= 8/15 

Nhớ tick nha

\(\dfrac{26}{39}=\dfrac{26:13}{39:13}=\dfrac{2}{3}\)
\(\dfrac{38}{57}=\dfrac{38:19}{57:19}=\dfrac{2}{3}\)

\(\dfrac{26}{39}=\dfrac{26:13}{39:13}=\dfrac{2}{3}\)

\(\dfrac{38}{57}=\dfrac{38:19}{57:19}=\dfrac{2}{3}\)

\(\dfrac{7}{5}-\dfrac{5}{16}\)
\(=\dfrac{112}{80}-\dfrac{25}{80}\)
\(=\dfrac{87}{80}\)

`7/5 - 5/16`

`=112/80 -25/80`

`=87/80`

120 trang

\(\dfrac{3}{16};\dfrac{5}{24};\dfrac{21}{56}\)

\(\dfrac{21}{56}=\dfrac{3}{8}=\dfrac{18}{48}\)

\(\dfrac{5}{24}=\dfrac{10}{48}\)

\(\dfrac{3}{16}=\dfrac{9}{48}\)

Ta quy đồng được thành: \(\dfrac{9}{48};\dfrac{10}{48};\dfrac{18}{48}\)

\(\dfrac{3}{16}\text{=}\dfrac{3\times21}{16\times21}\text{=}\dfrac{63}{336}\)

\(\dfrac{5}{24}\text{=}\dfrac{5\times14}{24\times14}\text{=}\dfrac{70}{336}\)

\(\dfrac{21}{56}\text{=}\dfrac{21\times6}{56\times6}\text{=}\dfrac{126}{336}\)

Bằng 2023