Question

tìm x , biết :   x + 30% x = -1,3 

Answer 1

Trả lời :

\(x+30\%\cdot x=-\frac{1}{3}\)

\(x+\frac{3}{10}\cdot x=-\frac{1}{3}\)

\(x\left(1+\frac{3}{10}\right)=-\frac{1}{3}\)

\(\frac{13}{10}x=-\frac{1}{3}\)

\(x=-\frac{1}{3}:\frac{13}{10}\)

\(x=-\frac{10}{39}\)

Vậy \(x=-\frac{10}{39}\)

Hok tốt

-Ken-

Answer 2

\(x+30\%x=-1,3\)

\(\Leftrightarrow1x+\frac{30}{100}x=-1,3\)

\(\Leftrightarrow\frac{10}{10}x+\frac{3}{10}x=-1,3\)

\(\Leftrightarrow x\left(\frac{10}{10}+\frac{3}{10}\right)=-1,3\)

\(\Leftrightarrow\frac{13}{10}x=\frac{-13}{10}\)

\(\Leftrightarrow x=\frac{-13}{10}\div\frac{13}{10}\)

\(\Leftrightarrow x=\frac{-13}{10}\times\frac{10}{13}\)

\(\Leftrightarrow x=-1\)