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Roots

by moonlite » Tue Apr 28, 2009 4:52 am
Can someone please help me solve this?

Thanks.

√[2√63 + 2/(8+3√7)] =

A. 8 + 3√7
B. 4 + 3√7
C. 8
D. 4
E. √7

OA D

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by sacx » Tue Apr 28, 2009 5:11 am
√[2√63 + 2/(8+3√7)]

= √[6√7 + 2/(8+3√7)]
= √2[3√7 + 1/(8+3√7)]
= √2[(24√7+63 + 1)/(8+3√7)]
=√2[(24√7+64)/(8+3√7)]
=√16[(3√7+8)/(8+3√7)]
= 4
SACX