Question

resolver cada cubo del Binomio

1.. (x+3)³

2.. (2m+6n)³

3.. (7a-5b)³​

Answer 1

Respuesta:

$1) \left(x+3\right)^3$

  $=x^3+3x^2\cdot \:3+3x\cdot \:3^2+3^3$

  $=x^3+9x^2+27x+27$

$2) \left(2m+6n\right)^3$

   $=\left(2m\right)^3+3\left(2m\right)^2\cdot \:6n+3\cdot \:2m\left(6n\right)^2+\left(6n\right)^3$

   $=8m^3+72m^2n+216mn^2+216n^3$

$3) \left(7a-5b\right)^3$

   $=\left(7a\right)^3-3\left(7a\right)^2\cdot \:5b+3\cdot \:7a\left(5b\right)^2-\left(5b\right)^3$

   $=343a^3-735a^2b+525ab^2-125b^3$