Question

Tính:

a) \(\sqrt{16.0,25}\);            b) \(\sqrt{2^4.\left(-7\right)^2}\);                c) \(\sqrt{0,9}.\sqrt{1000}\);              d) \(\sqrt{2}.\sqrt{5}.\sqrt{40}\).

Answer 1

a) \(\sqrt {16.0,25}  = \sqrt {16} .\sqrt {0,25}  = 4.0,5 = 2\)

b) \(\sqrt {{2^4}.{{( - 7)}^2}}  = \sqrt {{{( - 7)}^2}} .\sqrt {{2^4}}  = {7.2^2} = 28\)

c) \(\sqrt {0,9} .\sqrt {1000}  = \sqrt {0,9.1000}  = \sqrt {900}  = \sqrt {{{30}^2}}  = 30\)

d) \(\sqrt 2 .\sqrt 5 .\sqrt {40}  = \sqrt {2.5.40}  = \sqrt {400}  = \sqrt {{{20}^2}}  = 20\)