I get this far, and then i get stuck..i dont know what to do...when I multiply by (X + 8i), i keep getting the wrong answer..could someone please help me? Thank you
$\displaystyle \left( {x^2 - x - 12} \right)\left( {x^2 + 64} \right) =$$\displaystyle \left( {x^2 } \right)\left( {x^2 } \right) + \left( {x^2 } \right)\left( {64} \right) + \left( { - x} \right)\left( {x^2 } \right) + \left( { - x} \right)\left( {64} \right) + \left( { - 12} \right)\left( {x^2 } \right) + \left( { - 12} \right)\left( {64} \right)
$