Answers

2014-08-03T14:12:21+08:00
A^2-4 po 
a^4-16    
a^2+4      is equal to a^2-4
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2014-08-03T14:14:16+08:00
A^4-16
a²+4

a²-4

solution: \frac{a^4-16}{a²+4}  divide the two and minus the exponents
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