Question

Aflați x din proporția
a)x- 1/ 2x+10 =1 / 3 ,
b)x+ 1/ 3x-1 =1/ 2​

Answer 1

$\it a)\ \ \dfrac{x-1}{2x+10}=\dfrac{1}{3} \Rightarrow 3(x-1)=2x+10 \Rightarrow 3x-3=2x+10 \Rightarrow\\ \\ \Rightarrow 3x-2x=10+3 \Rightarrow x=13$

$\it b)\ \dfrac{x+1}{3x-1}=\dfrac{1}{2} \Rightarrow 2x+2=3x-1 \Rightarrow 2+1=3x-2x \Rightarrow x=3$

Answer 2

$\frac{x-1}{2x+10} =\frac{1}{3} \implies 3(x-1)=2x+10$

$\implies 3x-3=2x+10$

$\implies3x-2x-3=10$

$\implies3x-2x=10+3$

$\implies x=13$

$\frac{x+1}{3x-1} =\frac{1}{2} \implies2(x+1)=3x-1$

$\implies 2x+2=3x-1$

$\implies 2x-3x+2=-1$

$\implies 2x-3x=-1-2$

$\implies -x=-3\:|\cdot(-1)$

$\implies x=3$