2/135

=2/135

chuc hoc tot

minh xin loi 

\(\left|-34\right|+(-4)\cdot(-1)^{2008}+(17-19)^2\)

\(=34+4+(-2)^2\)

\(=34+4+4\)

\(=42\)

\((-31)\cdot81-18\cdot31-31\)

\(=31\cdot(-81)-18\cdot31-31\)

\(=31\cdot(-81)-18-1\)

\(=31\cdot(-100)=-3100\)

\(3420-(125+3420)+(-25+74)\)

\(=3420-125+3420-25+74\)

\(=3420+125-3420+25+74\)

\(=3420+(-3420)-125-25+74=-76\)

P/S : Hông chắc :< Hoq chắc :> Còn ba bài đó bạn tự  làm đi

a)29 . (19 – 13) – 19 . (29 – 13)

= 29 . 6 – 19 . 16

= 174 – 304

= –130.

b)31.(-18)+31.(-81)-31       

= 31. [-18 + (-81) - 1 ]

= 31. (-100)

= -3100

c)(7.3-3):(-6)  

(7.3-3):(-6)

= (21-3):(-6)

= 18 : (-6)

= 3

d)72:[(-6).2+4)]       

= 72 : ( -12 + 4 )

= 72 : -8

= -9

Bài 2:

a)(-12).47+(-12).52+(-12)       

= (-12).(47+52+1)

= -1200

b)13.(23+22)-3.(17+28)  

13 . (23 + 22) - 3 . (17 + 28)

= 13 . 45 - 3 . 45

= ( 13 - 3 ) . 45

= 10 . 45

= 450

c)18-10:(-2)-7   

= 18-5+7

= 13+7

= 20

d)99:[(-7).2+5)

1. Tính nhanh

a) 29 . (19 – 13) – 19 . (29 – 13)

= 29 . 6 – 19 . 16

= 174 – 304

= –130.

b) 31 . (-18) + 31 . (-81) - 31       

= 31. [-18 + (-81) - 1 ]

= 31. (-100)

= -3100

c) (7 . 3 - 3) : (-6)

= (21 - 3) : (-6)

= 18 : (-6)

= 3

d) 72 : [(-6) . 2 + 4)]       

= 72 : ( -12 + 4 )

= 72 : -8

= -9

2. Tính nhanh

a) (-12) . 47 + (-12) . 52 + (-12)

= (-12) . (47 + 52 + 1)

= (-12) . 100

= -1200        
b) 13 . (23 + 22) - 3 . (17 + 28)   

= 13 . 45 - 3 . 45

= (13 - 3) . 45

= 10 . 45

= 450
c) 18 - 10 : (-2) - 7   

= 18-5+7

= 13+7

= 20

d) 99 : [(-7) . 2 + 5]

= 99 : -9

= -11

\(a,31.\left(-18\right)+31.\left(-81\right)-31\)

\(=31\left(-18-81-1\right)\)

\(=31\left(-100\right)\)

\(=-3100\)

\(b,13\left(23+22\right)-3\left(17+28\right)\)

\(=299+286-51-84\)

\(=450\)

Cảm ơn

nhiều quá à

nhìn mk ko muốn làm

nhiều bài quá

chúc bn học gioi!

ahjhj

1> 31.(-18)+31.(-81)-31

=31(-18-81-1)

=31.-100

=-3100

a.    3, 63 + 5, 13 + 6 , 63 + 8, 13 + 9, 63 + 11 , 13

   = 8,76 + 6 , 63 + 8, 13 + 9, 63 + 11 , 13

   = 15,39 + 8, 13 + 9, 63 + 11 , 13

   = 23,52 + 9, 63 + 11 , 13

   = 33,15 + 11 , 13

   = 44,28

b. 135 , 7 + 20 , 4 + 4 , 6

= 156,1 + 4,6

= 160,7

b)135,7 + (20,4 + 4,6)

    135,7 +         25

           160,7

a) 3,63 + 5,13 + 6,63 + 8,13 + 9,63 + 11,13

=(3,63 + 11 ,13) + ( 5,13 + 9,63 ) + (6,63 +8,13)

=      14,76          +           14,76               +       14,76

= 14 , 76 x 3 

= 44,28

b) 135,7 + 20,4 + 4,6

= 135,7 + (20,4 + 4,6)

= 135,7 +     25

=160,7

a,\(\frac{31}{17}+\frac{5}{13}+\frac{8}{13}-\frac{14}{17}=\left(\frac{31}{17}-\frac{14}{17}\right)+\left(\frac{5}{13}+\frac{8}{13}\right)=1+1=2\)                                                              b,\(\frac{5}{7}.\frac{22}{11}+\frac{5}{7}.\frac{9}{11}+\frac{5}{7}=\frac{5}{7}.\left(\frac{22}{11}+\frac{9}{11}+1\right)=\frac{5}{7}.4=\frac{20}{7}\)

thank

a) \(\frac{31}{17}+\frac{5}{13}+\frac{8}{13}-\frac{14}{17}\)

    \(=\left(\frac{31}{17}-\frac{14}{17}\right)+\left(\frac{5}{13}+\frac{8}{13}\right)\)

     \(=1+1\)

      \(=2\)

b) \(\frac{5}{7}\cdot\frac{22}{11}+\frac{5}{7}\cdot\frac{9}{11}+\frac{5}{7}\)

    \(=\frac{5}{7}\cdot\left(\frac{22}{11}+\frac{9}{11}+1\right)\)

      \(=\frac{5}{7}\cdot\frac{42}{11}\)

        \(=\frac{30}{11}\)

\(=\dfrac{-3}{17}-\dfrac{2}{13}+\dfrac{20}{17}-\dfrac{11}{13}\)

=1-1

=0

\(-\left(\dfrac{3}{17}+\dfrac{2}{13}\right)-\left(\dfrac{-20}{17}+\dfrac{11}{13}\right)\)

\(=-\dfrac{3}{17}-\dfrac{2}{13}-\dfrac{20}{17}-\dfrac{11}{13}\)

\(=-\left(\dfrac{3}{17}+\dfrac{20}{17}\right)-\left(\dfrac{2}{13}+\dfrac{11}{13}\right)\)

\(=-\dfrac{23}{17}-1\)

\(=-\dfrac{40}{17}\)

\(-\left(\dfrac{3}{17}+\dfrac{2}{13}\right)-\left(\dfrac{-20}{17}+\dfrac{11}{13}\right)\)

⇔ \(\dfrac{-3}{17}-\dfrac{2}{13}+\dfrac{20}{17}-\dfrac{11}{13}\)

⇔ \(\left(\dfrac{-3}{17}+\dfrac{20}{17}\right)+\left(\dfrac{-2}{13}-\dfrac{11}{13}\right)\)

⇔ \(1+\left(-1\right)\)

⇔ \(0\)