Question

va rog ajutatimaaaaaaaaa va rog e urgent

Answer 1

   
[tex] a)~~4 \sqrt{5} -2\sqrt{5} +7\sqrt{5} =\sqrt{5} (4-2+7) = \boxed{9\sqrt{5}} \\ \\ b)~~5 \sqrt{7}-9 \sqrt{7}+4 \sqrt{7} = \sqrt{7}(5-9+4) =0 \sqrt{7} = \boxed{0} \\ \\ c)~~1,5 \sqrt{11}-14\sqrt{7}+0,5\sqrt{11}+6\sqrt{7}= \\ \sqrt{11}(1,5-0,5) + \sqrt{7}(-14+6) = \boxed{\sqrt{11} -8\sqrt{7}}[/tex]


[tex] \displaystyle \\ d)~~ \frac{1}{3} \sqrt{5} -\frac{3}{4} \sqrt{5} +\frac{2}{3}-0,(4) + \frac{1}{12} \sqrt{5}= \\ \\ =\sqrt{5}\Big( \frac{1}{3} -\frac{3}{4} + \frac{1}{12} \Big) +\frac{2}{3}- \frac{4}{9} = \\ \\ =\sqrt{5}\Big( \frac{4}{12} -\frac{9}{12} + \frac{1}{12} \Big) +\frac{6}{9}- \frac{4}{9} = \\ \\ = \boxed{-\frac{4}{12} \sqrt{5} +\frac{2}{9} }[/tex]