Question

Tính

a) √25 - √49/4 + √0,25

b)( -25/24 - 31/42 ) - ( -7/27 - 3/42 )

c) 103/10 - (9,5 - 0,25 . 18 ) : 0.5

d) (10³+15 . 10²+5³) :7

Answer 1

a) \(\sqrt{25}-\sqrt{\dfrac{49}{4}}+\sqrt{0,25}\)

\(=5-3,5+0,5\)

\(=2\)

b) \(\left(-\dfrac{25}{24}-\dfrac{31}{42}\right)-\left(\dfrac{-7}{27}-\dfrac{3}{42}\right)\)

\(=\dfrac{-25}{24}-\dfrac{31}{42}+\dfrac{7}{27}+\dfrac{3}{42}\)

\(=\left(\dfrac{-25}{24}+\dfrac{7}{27}\right)+\left(-\dfrac{31}{42}+\dfrac{3}{42}\right)\)

\(=-\dfrac{169}{216}+-\dfrac{2}{3}=-1\dfrac{97}{216}\)

c) \(\dfrac{103}{10}-\left(9,5-0,25.18\right):0,5\)

\(=10,3-\left(9,5-0,25.18\right):0,5\)

\(=10,3-5:0,5\)

\(=0,3\)

d) \(\left(10^3+15.10^2+5^3\right):7\)

\(=\left(10^3+10^2\right)\left(15+5^3\right):7\)

\(=\left(1100.140\right):7\)

\(=22000\)