Question

Tìm x

\(\dfrac{9+x}{13-x}\) = \(\dfrac{5}{6}\)

Answer 1

\(\dfrac{9+x}{13-x}=\dfrac{5}{6}\\ \Rightarrow5\left(13-x\right)=6\left(9+x\right)\\ \Rightarrow65-5x=54+6x\\ \Rightarrow6x+5x=65-54\\ \Rightarrow11x=11\\ \Rightarrow x=1\)

Vậy x = 1

Answer 2

ĐKXĐ: \(x\ne13\)

\(\dfrac{9+x}{13-x}=\dfrac{5}{6}\)

\(\Leftrightarrow\dfrac{6\left(9+x\right)}{6\left(13-x\right)}=\dfrac{5\left(13-x\right)}{6\left(13-x\right)}\)

\(\Rightarrow6\left(9+x\right)=5\left(13-x\right)\)

\(\Leftrightarrow54+6x=65-5x\)

\(\Leftrightarrow6x+5x=65-54\)

\(\Leftrightarrow11x=11\)

\(\Leftrightarrow x=1\) (thỏa mãn ĐKXĐ)

Answer 3

\(\dfrac{9+x}{13-x}=\dfrac{5}{6}\\ \Rightarrow6\left(9+x\right)=5\left(13-x\right)\\ \Leftrightarrow54+6x=65-5x\\ \Leftrightarrow11x=11\\ \Leftrightarrow x=1\)

Vậy \(x=1\)

Answer 4

\(\dfrac{9+x}{13-x}=\dfrac{5}{6}\)

⇔ \(\left(9+x\right).6=\left(13-x\right).5\)

⇔ \(54+6x=65-5x\)

⇔ \(6x+5x=-54+65\)

⇔ \(11x=11\)

⇔ \(x=1\)

Vậy x = 1