Question

1. tính:

a, \(\sqrt{a^2}\) với a = 2,5; 0,3; -0,1 ; b, \(\sqrt{a^4}\) với a = -1,3; 2,1; -0,4

2. tính:

a, \(\sqrt{10^2-6^2}\) b, \(\sqrt{17^2-8^2}\) c, \(\sqrt{2,9^2-2,1^2}\)

d, \(\sqrt{\dfrac{13^2-6^2}{81}}\) e, \(\sqrt[]{\dfrac{6,2^2-5,9^2}{2,43}}\) g, \(\sqrt{\dfrac{9^3+7^3}{9^2-9.7+7^2}}\)

3. Tính.

a,\(\sqrt{\dfrac{1,96}{2,25}}\) b, \(\sqrt{1\dfrac{13}{36}.1\dfrac{32}{49}}\) c, \(\sqrt{\dfrac{1}{9}.0,09.64}\)

4. Tính.

a, \(\dfrac{\sqrt{10,8}}{\sqrt{0,3}}\) b,\(\dfrac{\sqrt{7}}{\sqrt{175}}\) c,\(\dfrac{\sqrt{2,84}}{\sqrt{0,71}}\) d, \(\dfrac{\sqrt{6,25}}{\sqrt{1,44}}\)

Answer 1

1. với a=2,5 thì \(\sqrt{a^2}\) =\(\left|a\right|=\)\(\left|2.5\right|=2.5\)

với a=0,3 thì \(\sqrt{a^2}\) =\(\left|a\right|=\)\(\left|0,3\right|=0,3\)

với a=-0,1 thì \(\sqrt{a^2}\) =\(\left|a\right|=\)\(\left|-0,1\right|=0,1\)

Answer 2

Bài 4: 

a: \(=\sqrt{\dfrac{10.8}{0.3}}=\sqrt{36}=6\)

b: \(=\sqrt{\dfrac{7}{175}}=\sqrt{\dfrac{1}{25}}=\dfrac{1}{5}\)

c: \(=\sqrt{\dfrac{2.84}{0.71}}=2\)

d: \(=\sqrt{\dfrac{625}{144}}=\dfrac{25}{12}\)