Question

Вычислите:
а) $-3 sqrt{1,69} + frac{1}{2} (sqrt{6})^{2}$
б) $-5 sqrt{3 frac{1}{16} }-2 sqrt{3 frac{6}{25} }$ 
в)$(sqrt{12} - sqrt{2})^{2}$

Answer 1

$-3 sqrt{1,69} + frac{1}{2} (sqrt{6})^{2}=-3*1,3+frac{1}{2}*6=-3,9+3=-0,9$

$-5 sqrt{3 frac{1}{16} }-2 sqrt{3 frac{6}{25} } = -5 sqrt{frac{49}{16} }-2 sqrt{frac{81}{25}}=\ =-5*frac{7}{4}}-2*frac{9}{5}}=-frac{35}{4}}-frac{18}{5}}=-8frac{3}{4}}-3frac{3}{5}}=\ =-8frac{15}{20}}-3frac{12}{20}}=-11frac{27}{20}}=-12frac{7}{20}}$

$(sqrt{12} - sqrt{2})^{2}=(sqrt{12})^2-2sqrt{12}*sqrt{2}+(sqrt{2})^2=12-2sqrt{24}+2=14-4sqrt{6}$