Respostas

2013-12-01T18:38:22-02:00
A)  \frac{3x}{x-4} =  \frac{3x+2}{x} <=>  \frac{3x^{2} }{ x^{2}-4x } =  \frac{3x ^{2} -10x-8}{ x^{2}-4x } <=>

<=> 3 x^{2} -3 x^{2} = -10x - 8 <=> 10x = 8 <=> x = 8/10 <=> x = 4/5

B)  \frac{5}{y^{2}-9 } =  \frac{-3y+9}{y ^{2}-9 } <=>

5 = -3y + 9 <=>
<=> 5 - 9 = -3y <=>
y = 4/3