Respostas

  • Usuário do Brainly
2014-07-28T23:31:33-03:00
A)
 \frac{ x^{2} -3x-4}{3x+3}= \frac{(x-4)(x+1)}{3(x+1)} = \frac{x-4}{3}

Cancela (x+1)

b)

 \frac{ x^{2} -7x}{ x^{2} +3x-70} = \frac{x(x-7)}{(x-7)(x+10)} = \frac{x}{x+10}

cancela (x-7)