Question

Aratati ca numarul b=√5-2√6+√5+2√6-√(4+2√3)² este intreg

Answer 1

$b = \sqrt{5} - 2 \sqrt{6} + \sqrt{5} + 2 \sqrt{6} - \sqrt{ {(4 + 2 \sqrt{3}) }^{2} }$

$b = 2 \sqrt{5} - |4 + 2 \sqrt{3} |$

$b = 2 \sqrt{5} - (4 + 2 \sqrt{3} )$

$b = 2 \sqrt{5} - 4 - 2 \sqrt{3}$

$b = 2 \times 2.23 - 4 - 2 \times 1.73$

$b = 4.46 - 4 - 3.46$

$b = 0.46 - 3.46$

$b = - 3$