Simplify \(\frac{5+\sqrt{7}}{3+\sqrt{7}}\)
A
17-√7
B
4-√7
C
15+√7
D
7-√7
Verified Correct Answer: B.
Step-by-Step Mathematical Solution
\(\frac{5+\sqrt{7}}{3+\sqrt{7}}=\frac{5+\sqrt{7}}{3+\sqrt{7}}\times \frac{3-\sqrt{7}}{3-\sqrt{7}}\)
=\(\frac{(5+\sqrt{7})(3-\sqrt{7})}{3^2 - \sqrt{7}^2}\)
=\(\frac{15-5\sqrt{7}+3\sqrt{7}-7}{9-7}\)
= \(\frac{8-2\sqrt{7}}{2}\)
Factorize, then divide by 2
\(=\frac{2(4-\sqrt{7}}{2})\)
=4-\(\sqrt{7}\)
Source: Myschool Past Questions Archive (Record #9311)