hey guys, just doin a lil study..im a little confused about these questions.
factor these two questions:
1)
$\displaystyle
81x^2 - 16y^2
$
2)
$\displaystyle
(y+3)^3 + 8
$
any ideas?
Considering that you seem to be focusing on difference of squares, sum and difference of cubes, the intention is probably, for #2, that you recognize that $\displaystyle (y+3)^3 + 8$ is a difference of cubes and use that formula (where $\displaystyle a = (y + 3), b = 2$). You can do it the other way - multiply it all out - as well.