Question

lim x-1 (2x-1)³ + 27 /x+1

Answer 1

Resposta:

Lim   [(2x-1)³+27]/(x+1)

x--> -1

(a+3)³=a³+9a²+27a+27

a³+27=(a+3)³-9a*(a+3)

a³+27=(a+3)*[(a+3)²-9a]

a³+27=(a+3)*(a²+9-3a)

Fazendo a=2x-1

(2x-1)³+27 = (2x+2)*[(2x-1)²+9-3*(2x-1)]

Lim  (2x+2)*[(2x+1)²+9-3*(2x-1)]/(x+1)

x--> -1

Lim  2*(x+1)*[(2x-1)²+9-3*(2x-1)]/(x+1)

x--> -1

Lim  2[(2x-1)²+9-3*(2x-1)]

x--> -1

=2*[(-2-1)²+9-3*(-2-1)]

=2*(9+9+9)

= 54   é a resposta