Question

a) \(\dfrac{2}{5}\sqrt{25}\) -\(\dfrac{1}{2}\sqrt{4}\)       b)0,5\(\sqrt{0,09}\) +5\(\sqrt{0,81}\)       c)\(\dfrac{2}{5}\sqrt{\dfrac{25}{36}}\) -\(\dfrac{5}{2}\sqrt{\dfrac{4}{25}}\)

d)-2\(\sqrt{\dfrac{-36}{-16}}\) + 5\(\sqrt{\dfrac{-81}{-25}}\)

Answer 1

`#3107.101107`

a)

`2/5 \sqrt{25} - 1/2 \sqrt{4}`

`= 2/5 * \sqrt{5^2} - 1/2 * \sqrt{2^2}`

`= 2/5*5 - 1/2*2`

`= 2 - 1`

`= 1`

b)

`0,5*\sqrt{0,09} + 5*\sqrt{0,81}`

`= 0,5*\sqrt{(0,3)^2} + 5*\sqrt{(0,9)^2}`

`= 0,5*0,3 + 5*0,9`

`= 0,15 + 4,5`

`= 4,65`

c)

`2/5\sqrt{25/36} - 5/2\sqrt{4/25}`

`= 2/5*\sqrt{(5^2)/(6^2)} - 5/2*\sqrt{(2^2)/(5^2)}`

`= 2/5*5/6 - 5/2*2/5`

`= 1/3 - 1`

`= -2/3`

d)

`-2 \sqrt{(-36)/(-16)} + 5 \sqrt{(-81)/(-25)}`

`= -2*\sqrt{36/16} + 5*\sqrt{81/25}`

`= -2*\sqrt{(6^2)/(4^2)} + 5*\sqrt{(9^2)/(5^2)}`

`= -2*6/4 + 5*9/5`

`= -3 + 9`

`= 6`