k minh minh giai

* (-6 - 2) . (-6 + 2)

=    -8   .     -4

=           32

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

=      18    : (-6)

=            -3

k cho mik nhe

(-6-2).(-6+2)

=-8.(-4)

=32

(7.3-3):(-6)

=(21-3):(-6)

=18:(-6)

=-3

(-5+9).(-4)

=4.(-4)

=-16

72:(-6.2+4)

=72.(-12+4)

=72.8

-3.7-4.(-5)+1

=-21+20+1

=-1+1

=0

18-10:(+2)-7

=18-5-7

=13-7

=6

15:(-5).(-3)-8

=-3.(-3)-8

=9-8

=1

(6.8-10:5)+3.(-7)

=(48-2)+3.(-7)

=46+(-21)

=25

a, (-6-2).(-6+2)

=(-6)²-2²

=36-4

=32

Mấy câu kia dễ mà bn tự lm nha

a, ( -6 - 2 ) . ( -6 + 2 )

= -8 . ( -4 )

= 32

Mấy câu kia tương tự

#hoc_tot#

a) \(\left(-5+9\right).\left(-4\right)\)

\(=4.\left(-4\right)\)

\(=-16\)

b) \(72\div\left(-6.2+4\right)\)

\(=72\div\left(-12+4\right)\)

\(=72\div\left(-8\right)\)

\(=-9\)

c) \(-3.7-4.\left(-5\right)+1\)

\(=-21-\left(-20\right)+1\)

\(=-1+1\)

\(=0\)

1. (-6 - 2).(-6 + 2)=(-6 - 2)=-8;(-6 + 2)=-8

=>-8+-8=-16

2. (7.3-3) : (-6)=(7.3-3)=18 : (-6)=-3

3. (-5+9).(-4)=(-5+9)=4.(-4)=-16

4. 72:(-6.2+4)=72 : -8=-9

bấm máy tính hết là ra chứ j! 

tại sao câu 1 căn cứ vào đâu mà lại bằng (-6-2)

a)1/2 + 5/6 + 11/12 + 19/20 + 29/30 + 41/42 + 55/56 + 71/72+89/90

=1-1/2+1-1/6+1-1/12+1-1/20+1-1/30+1-1/42+1-1/56+1-1/72+1-1/90

=9 – (1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90)

=9 – [1/(1x2)+1/(2x3)+1/(3x4)+1/(4x5)+1/(5x6)+1/(6x7)+1/(7x8)+1/(8x9)+1/(9x10)]

=9 – ( 1-1/2+1/2-1/3+1/3-1/4+1/4-1/5+1/5-1/6+1/6-1/7+1/7-1/8+1/8-1/9+1/9-1/10)

=9 – (1 – 1/10) = 9 – 9/10 = 81/10

b)4/3.7 + 4/7.11 + 4/11.15 + 4/15.19 + 4/19.23 + 4/23.27

=4.(4/3.7 + 4/7.11 + ........+ 4/23.27 )

=1.( 1/3.7 + 1/7.11 + ......+ 1/23.27 )

=1.(1/3 - 1/7 + 1/7 - 1/11 +............ + 1/23 - 1/27 )

=1.(1/3 - 1/27 )

=1.(9/27 - 1/27)

=1.8/27

=8/27

c)1/10+1/40+1/88+1/154+1/138+1/340

=1/2.5 + 1/5.8 + 1/11.8 + 1/11.14 + 1/14.17 + 1/17.20

=1/3. (3/2.5  + 3/5.8 + 3/8.11 + 3/11.14 + 3/14.17 + 3/17.20 )

=1/3. ( 1/2 - 1/5 + 1/5 - 1/8 + 1/8 - 1/11 + 1/11 - 1/14 + 1/14 - 1/17 + 1/17 -1/20 )

=1/3. ( 1/2 - 1/20 )

=1/3. 9/20

=3/20

P/S: CHÚC HOK TỐT !

giupmimnhdi

a)  \(0,75+\left(\dfrac{-1}{3}\right)-\dfrac{5}{18}=\dfrac{3}{4}+\left(\dfrac{-1}{3}\right)-\dfrac{5}{18}=\dfrac{5}{12}-\dfrac{5}{18}=\dfrac{5}{36}\)

c) \(\dfrac{4}{15}\cdot\dfrac{1}{3}\cdot\dfrac{15}{20}=\dfrac{4}{15}\cdot\dfrac{1}{3}\cdot\dfrac{3}{4}=\dfrac{5}{45}\cdot\dfrac{3}{4}=\dfrac{15}{180}=\dfrac{1}{12}\)

d) \(\left(\dfrac{-1}{9}\right)\cdot\left(\dfrac{15}{22}\right):\left(\dfrac{-25}{9}\right)=\dfrac{-5}{66}:\left(\dfrac{-25}{9}\right)=\dfrac{-5}{66}\cdot\left(\dfrac{9}{-25}\right)=\dfrac{-3}{-110}=\dfrac{3}{110}\)

a) \(0,75\) + \(\dfrac{-1}{3}\) - \(\dfrac{5}{18}\)= \(\dfrac{5}{12}\) - \(\dfrac{5}{18}\) = \(\dfrac{5}{36}\)

b) \(\dfrac{4}{15}\)x \(\dfrac{1}{3}\)x \(\dfrac{15}{20}\)= 4/45 x 15/20 = 1/15

c) -1/9 x 15/22 : -25/9 = -5/66 : -25/9 = 3/110

\(a.0,75+\left(\dfrac{-1}{3}\right)-\dfrac{5}{18}=\dfrac{75}{100}+\left(\dfrac{-6}{18}\right)-\dfrac{5}{18}=\dfrac{3}{4}-\dfrac{11}{18}=\dfrac{5}{36}\\ b.\dfrac{4}{15}.\dfrac{1}{3}.\dfrac{15}{20}=\dfrac{4}{15}.\dfrac{1}{3}.\dfrac{3}{4}=\dfrac{4.1.3}{15.3.4}=\dfrac{1.1.1}{15.1.1}=\dfrac{1}{15}\\ c.\dfrac{-1}{9}.\dfrac{15}{22}:\left(\dfrac{-25}{9}\right)=\dfrac{-1}{9}.\dfrac{15}{22}.\dfrac{-9}{25}=\dfrac{\left(-1\right).15.\left(-9\right)}{9.22.25}=\dfrac{\left(-1\right).3.\left(-1\right)}{1.22.5}=\dfrac{3}{110}\)