Respostas

  • Usuário do Brainly
2014-08-17T01:41:49-03:00
A)

 \frac{x+1}{x-3} =5

multiplica cruzado

5(x-3)=x+1

5x-15=x+1

5x-x=1+15

4x=16

x= \frac{16}{4}

x=4

S={4}

b)

 \frac{x+10}{2} = \frac{4x-2}{x-2}

(x+10)(x-2)=2(4x-2)

 x^{2} -2x+10x-20=8x-4

 x^{2} +8x-8x=-4+20

 x^{2} =16

x= \sqrt{16}

x= ± 4

S={-4,4}
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  • Usuário do Brainly
2014-08-17T01:57:56-03:00
A) \dfrac{x+1}{x-3}=5

Temos que, x+1=5(x-3)

x+1=5x-15

5x-x=1+15

Deste modo, 4x=16 e x=\dfrac{16}{4}=4

S=\{4\}.

b) \dfrac{x+10}{2}=\dfrac{4x-2}{x-2}

(x+10)(x-2)=2(4x-2)

x^2+8x-20=8x-4

Assim, x^2=20-4=16, ou seja, x=\pm\sqrt{16}.

Logo, x=\pm4.

S=\{-4, 4\}
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