Question

Tìm x , biết :

\(\frac{x}{2}=\frac{15}{20}\)

ai làm nhanh nhất mik tik ạ 

Answer 1

Ta có: \(\frac{x}{2}=\frac{15}{20}\Leftrightarrow\frac{10x}{20}=\frac{15}{20}\Leftrightarrow10x=15\Leftrightarrow x=\frac{3}{2}\)

Vậy \(x=\frac{3}{2}\)

Answer 2

\(\Rightarrow\)\(\frac{x}{2}\)=\(\frac{3}{4}\)

x.4=2.3

x.4=6

x   =6:4

\(\Rightarrow\)x=\(\frac{6}{4}\)=\(\frac{3}{2}\)

\(\Rightarrow\)x=3

Answer 3

Ta có : \(\frac{15}{20}\)\(=\)\(\frac{15:5}{20:5}\)\(=\)\(\frac{3}{4}\)

Vì  \(\frac{x}{2}\)\(=\)\(\frac{15}{20}\)\(\Rightarrow\)\(\frac{x}{2}\)\(=\)\(\frac{3}{4}\) 

\(\Rightarrow\)x . 4  \(=\)3 . 2 \(\Rightarrow\)x.4  \(=\)6

\(\Rightarrow\)x \(=\)6 : 4 \(\Rightarrow\)x \(=\)\(\frac{6}{4}\)\(=\)\(\frac{3}{2}\)

Vậy   x \(=\)\(\frac{3}{2}\)

Answer 4

\(\frac{x}{2}\)= \(\frac{15}{20}\)

x x 20 = 15 x 2

x x 20 = 30

x = 30 : 20

x = 1,5