1. ## Quick Question

Hi
Can someone tell me how i would work this out:

Express the following in the form$\displaystyle x+y\sqrt2$ with x and y rational numbers:
$\displaystyle (7+5\sqrt2)^3$

P.S

2. Use the formula $\displaystyle (a+b)^3=a^3+3a^2b+3ab^2+b^3$