Oblicz.
a)
[tex](5 - \sqrt{7)(5 + \sqrt{7)} } [/tex]
b)
[tex]( \sqrt{5 + 1)(1 - \sqrt{5)} } [/tex]
c)
[tex]( \frac{1}{3} + \sqrt{ \frac{ \sqrt{6} }{2} })( \frac{1}{3} - \frac{ \sqrt{6} }{2})[/tex]
d)
[tex](2 \sqrt{2} - 3)(3 + 2 \sqrt{2})[/tex]
​