(begin{array}{l}a)2.sqrt 6 .( – sqrt 6 );\b)sqrt {1,44} – 2.{(sqrt {0,6} )^2};\c)0,1.{(sqrt 7 )^2} + sqrt {1,69} ;\d)( – 0,1).{(sqrt {120} )^2} – frac{1}{4}.{(sqrt {20} )^2}end{array})
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Lời giải chi tiết
(begin{array}{l}a)2.sqrt 6 .( – sqrt 6 )\ = – 2.sqrt 6 .sqrt 6 \ = – 2.{(sqrt 6 )^2}\ = – 2.6\ = – 12\b)sqrt {1,44} – 2.{(sqrt {0,6} )^2}\ = 1,2 – 2.0,6\ = 1,2 – 1,2\ = 0\c)0,1.{(sqrt 7 )^2} + sqrt {1,69} \ = 0,1.7 + 1,3 \= 0,7 + 1,3 \= 2\d)( – 0,1).{(sqrt {120} )^2} – frac{1}{4}.{(sqrt {20} )^2} \= ( – 0,1).120 – frac{1}{4}.20\ = – 12 – 5\ = – (12 + 5)\ = – 17end{array})