b) Ma=4-2V3+4+2V3/2= 4
Mg=radical mare din 4-2V3×4+2V3=radical mare din 4-6V3
c)
[tex] \sqrt{15 - 6 \sqrt{6} } + \sqrt{7 - 2 \sqrt{6 } } = \sqrt{(3 - { \sqrt{6} }^{} } ) {}^{2} + \sqrt{(1 - \sqrt{6} } ) {}^{2} = 3 - \sqrt{6} + \sqrt{6} - 1 = 2[/tex]
d) (n-3)(n²+3n+9)= n³-3³=n³-27
e) (a+3)×(a-5)
f) (5-k²)=5+k²
25-10k+k²=5+k²
25-10k=5
-10k=5-25
-10k= -20/×(-1)
k=2