\(1\frac{1}{2}\div x-4=0,5.\)

\(\frac{3}{2}\div x=0,5+4\)

\(\frac{3}{2}\div x=4,5\)

\(x=\frac{3}{2}\div4,5\)

\(x=\frac{1}{3}\)

Trả lời

\(\frac{3}{20}\)\(=\frac{3x5}{20x5}\)\(=\frac{15}{100}\)\(=0,15\)

\(\frac{30}{25}\)\(=\frac{30:5}{25:5}\)\(=\frac{6}{5}\)\(=\frac{6x2}{5x2}\)\(=\frac{12}{10}\)\(=1,2\)

Chúc bạn học tốt

3/20=0,15 ; 30/25=1,2

Theo đề ra, ta có: \(\frac{2x-y}{x+y}=\frac{2}{3}\)

\(\Rightarrow3\left(2x-y\right)=2\left(x+y\right)\)

\(\Rightarrow6x-3y=2x+2y\)

\(\Rightarrow4x=5y\)

\(\Rightarrow\frac{x}{y}=\frac{5}{4}\)

Mình cần gấp ai làm được mình rất chân thành cảm ơn 

GTNN là gì vậy??

\(B=\left|2x+3,5\right|+\left|2x+\frac{7}{2}\right|\)

\(=\left|3,5-2x\right|+\left|2x+3,5\right|\ge\left|3,5-2x+2x+3,5\right|=7\)

Dấu '' = '' xảy ra khi \(\left(3,5-2x\right)\left(2x+3,5\right)\ge0\)

\(\Rightarrow\orbr{\begin{cases}3,5-2x\ge0;2x+3,5\ge0\\3,5-2x\le0;2x+3,5\le0\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}2x\le3,5;2x\ge-3,5\\2x\ge3,5;2x\le-3,5\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}x\le1,75;x\ge-1,75\Rightarrow-1,75\le x\le1,75\\x\ge1,75;x\le-1,75\text{(Vô lý)}\end{cases}}\)

Vậy \(MinB=7\Leftrightarrow-1,75\le x\le1,75\)

\(\left|2x-4\right|=\left|5x+3\right|\)

\(\Rightarrow\orbr{\begin{cases}2x-4=5x+3\\2x-4=-5x+3\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}2x-4=5x+3\\2x-5x=-5x-3\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}2x-5x=3+4\\2x+5x=-3+4\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}-3x=7\\7x=1\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}x=\frac{-7}{3}\\x=\frac{1}{7}\end{cases}}\)