Question

Bài 7 (trang 10 SGK Toán 9 Tập 1)

Tính:

a) $\sqrt{(0,1)^2}$ ;     b) $\sqrt{(-0,3)^2}$ ;    c) $-\sqrt{(-1,3)^2}$ ;    d) $-0,4\sqrt{(-0,4)^2}$.

Answer 1

a, \(\sqrt{\left(0,1\right)^2}=\left|0,1\right|=0,1\)do \(0,1>0\)

b, \(\sqrt{\left(-0,3\right)^2}=\sqrt{\left(0,3\right)^2}=\left|0,3\right|=0,3\)do \(0,3>0\)

c, \(-\sqrt{\left(-1,3\right)^2}=-\sqrt{\left(1,3\right)^2}=-\left|1,3\right|=-1,3\)do \(1,3>0\)

d, \(-0,4\sqrt{\left(-0,4\right)^2}=-0,4\sqrt{\left(0,4\right)^2}=-0,4.\left|0,4\right|=-0,4.0,4=-0,14\)

do \(0,4>0\)

Answer 2

\(\sqrt{\left(0,1\right)^2}=\left|0,1\right|=0,1\)

\(\sqrt{\left(-0,3\right)^2}=\left|-0,3\right|=0,3\)

\(-\sqrt{\left(-1,3\right)^2}=-\left|-1,3\right|=-1,3\)

\(-0,4\sqrt{\left(-0,4\right)^2}=-0,4\cdot\left|-0,4\right|=-0,16\)

Answer 3

\(\sqrt{\left(0.1\right)^2^{ }}=0.1\)

Answer 4

45

Answer 5

\(\sqrt{\left(0.1\right)^2=0.1}\) TT TA CÓ 0.3 ;1.3 -0.16

Answer 6

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

b)  \(\sqrt{\left(-0,3\right)^2}\) = \(|\)-0,3\(|\)

c)  \(-\sqrt{\left(-1,3\right)^2}\) = -\(|\)-1,3\(|\) = -1,3

d) \(-0,4\sqrt{\left(-0,4\right)^2}\) = -0,4\(|\)-0,4\(|\)=-0,14

Answer 7

a) √(0,1)^2 = | 0,1| = 0,1

b) √(-0,3)^2 = |-0,3|= 0,3

c) -√(-1,3)^2 =| -1,3| = 1,3 

d) -0,4√(-0,4)^2 = | -√0,4. (-0,4) | = -2√10/25

   

Answer 8

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

b) \(\sqrt{\left(-0,3\right)^2}=\left|-0,3\right|=0,3\)

c) \(-\sqrt{\left(-1,3\right)^2}=-\left|-1,3\right|=-1,3\)

d) \(-0,4\sqrt{\left(-0,4\right)^2}=-0,4\left|-0,4\right|=-0,4.0,4=-0,16\)

Answer 9

a) 0,1

b) 0,3

c) -1,3

d) -0,16

Answer 10

a, vì 0,1 > 0 => A=0,1

b, vì -0.3 < 0 => B= /-0,3/ = 0,3

c, vì -1,3 <0 => B= -/-1,3/ = 1,3

d, vì -0,4 < 0 => D = -0,4./0,4/ = -0,14

Answer 11

Answer 12

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

b) \(\sqrt{\left(-0,3\right)^2}=|-0,3|=0,3\)

c) \(-\sqrt{\left(-1,3\right)^2}=-|-1,3|=-1,3\)

d) \(-0,4\sqrt{\left(-0,4\right)^2}=-0,4|-0,4|=-0,4.0,4=-0,16\)

Answer 13

a) 0,1; b) 0,3; c) -1,3; d) -0,16

Answer 14

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

b)\(\sqrt{\left(-0,3\right)^2}=|-0,3|=0,3\)

c)\(-\sqrt{\left(1,3\right)^2}=|-1,3|=1,3\)

d)\(-0,4\sqrt{\left(-0,4\right)^2}=-0,4.|-0,4|=-0,16\)

Answer 15

a.0,1

b.0,3

c.-1,3

d.-0,16

 

Answer 16

a) \sqrt{(0,1)^2}=|0,1|=0,1(0,1)2​=∣0,1∣=0,1.

b) \sqrt{(-0,3)^2}=|-0,3|=0,3(−0,3)2​=∣−0,3∣=0,3.

c) -\sqrt{(-1,3)^2}=-|-1,3|=-1,3−(−1,3)2​=−∣−1,3∣=−1,3.

d) -0,4\sqrt{(-0,4)^2}=-0,4|-0,4|=-0,4.0,4=-0,14−0,4(−0,4)2​=−0,4∣−0,4∣=−0,4.0,4=−0,14.

Answer 17

Answer 18

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

b, \(\sqrt{\left(-0,3\right)^2}\) = \(|-0,3|\) = 0,3

c, -\(\sqrt{\left(-1,3\right)^2}\) = -\(\left|-1,3\right|\) = -1,3

d, -0,4\(\sqrt{\left(-0,4\right)^2}\) = -0,4.\(\left|-0,4\right|\) = -0,4. 0,4 = -0,16

Answer 19

a)\(\sqrt{\left(0,1\right)^2}=0,1\)

b$\sqrt{{\left(-0,3\right)}^2}$ =0,3

c) -1,3

d)-0,16

 

Answer 20

a) 0,1   b) 0,3   c) -1,3   d) -0,16

Answer 21

Answer 22

Answer 23

a. \(\sqrt{\left(0,1\right)^2}\) = |0,1| = 0,1
b.\(\sqrt{\left(-0,3\right)^2}\) = |-0,3| = 0,3
c.\(-\sqrt{\left(-1,3\right)^2}\) = -|-1,3| = -1,3
d. \(-0,4\sqrt{\left(-0,4\right)^2}\) = -0,4|-0,4| = -0,4.0,4 = -0,14

Answer 24

Answer 25

a, 0,1

b,0,3

c, -1,3

d, -0,6

Answer 26

a) \(\sqrt{\left(0,1\right)^2}\) =\(\)∣0,1∣=0,1

b)\(\sqrt{\left(-0,3\right)^2}\)$=|-0,3|=0,3$

c)-\(\sqrt{\left(-1,3\right)}^2\) $=-|-1,3|=-1,3$

d)-0,4\(\sqrt{\left(-0,4\right)^2}\)=−0,4∣−0,4∣=−0,4.0,4=−0,14

 

Answer 27

a,0,1      b,0,3       c,-1,3        d,-0,16

Answer 28

Answer 29

a) 0.1
b) 0.3
c) -1.3
d) -0.16

Answer 30

a) $\sqrt{(0,1{)}^2}=|0,1|=0,1$.

b) $\sqrt{(-0,3{)}^2}=|-0,3|=0,3$.

c) $-\sqrt{(-1,3{)}^2}=-|-1,3|=-1,3$.

d) $-0,4\sqrt{(-0,4{)}^2}=-0,4|-0,4|=-0,4.0,4=-0,14$.