Question

calcule o valor de x usando propriedade fundamental 

1/3x=2/x+1 
2x-5/7x=3/10
x-2/x-3=3/5 ajudem pf

Answer 1

a) $\dfrac{1}{3x}=\dfrac{2}{x+1}$

$6x=x+1$

$5x=1$

$\boxed{x=\dfrac{1}{5}}$

b) $\dfrac{2x-5}{7x}=\dfrac{3}{10}$

$21x=20x-50$

$\boxed{x=-50}$

c) $\dfrac{x-2}{x-3}=\dfrac{3}{5}$

$3(x-3)=5(x-2)$

$3x-9=5x-10$

$5x-3x=10-9$

$2x=1$

$\boxed{x=\dfrac{1}{2}}$

Answer 2

$\frac{1}{3x}=\frac{2}{x+1}\\ \\ Propriedade \ fundamental:\\ \\ 2*3x=1(x+1)\\ \\ 6x=x+1\\ \\ 6x-x=1\\ \\ 5x=1\\ \\ \boxed{x=\frac{1}{5}}$

$\frac{2x-5}{7x}=\frac{3}{10}\\ \\ Propriedade \ fundamental:\\ \\ 10(2x-5)=3*7x\\ \\ 20x-50=21x\\ \\ 20x-21x=50\\ \\ -x=50\\ \\ \boxed{x=-50}[$

$\frac{x-2}{x-3}=\frac{3}{5}\\ \\ Propriedade \ fundamental:\\ \\ 5(x-2)=3(x-3)\\ \\ 5x-10=3x-9\\ \\ 5x-3x=-9+10\\ \\ 2x=1\\ \\ \boxed{x=\frac{1}{2}}$