## evergirl Group Title Rationalize the denominator of .......... one year ago one year ago

1. evergirl

2. mark_o.

$\frac{ 4 }{ 2+7i }*\frac{ 2-7i }{ 2-7i }$ $\frac{ 8-28i }{ ? }$ can you try to do the denominator

3. mark_o.

what did you get?... :D

4. mark_o.

the numerator is = 4(2-7i) = 8-28i yes or no? next the denominator is = (2+7i)(2-7i)= ______________?

5. mark_o.

if we have (a+b)(a-b)=a^2-b^2 also if we have (a+bi)(a-bi)=[a^2-(bi]^2 did you get this one ? yes or no?... :D

6. mark_o.

@ evergirl what did you get?