a) 66 x 25 + 5 x 66 + 66 x 14 + 33 x 66

= 66 x ( 25 + 5 + 14 + 66 )

= 66 x 110

= 7260

b) 35 x 25 + 35 x 41 + 64 x 65

=> không tính nhanh được

c) 325 x 6 + 6 x 560 + 115

= 6 x ( 325 + 560 ) + 115

= 6 x ( 885 + 115 )

= 6 x 1000

= 6000

d) 133 : 7 + 154 : 7 + 413 : 7

= 19 + 22 + 59

= 100

Đáp án :

a)66 x 25 + 5 x 66 x 14 + 33 x 66

=66 x ( 25 + 14 + 66 )

= 66 x 100

b)35 x 23 + 35 x 41 + 64 x 65 

= 35 x ( 23 + 41 ) + 64 x 65

= 35 x 64 + 64 x 65 

= 64 x ( 35+ 65 )

= 64 x 100

= 6400

c) 325 x 6 + 6 x 560 + 115 

= 6 x ( 325 + 560 ) + 115

= 6x ( 885 + 15 )

= 6 x 1000 

= 6000

d) 133 : 7 + 154 : 7 + 413 : 7 

= ( 133 + 154 + 413 ) : 7 

= 700 : 7

= 100 

mk làm được hết đó!!

ý a sai hết rồi, là 66*77 ms đúng

4) \(\left(\dfrac{3}{7}\right)^2\cdot\left(-7\right)^4\)

\(=\left(\dfrac{3}{7}\right)^2\cdot\left[\left(-7\right)^2\right]^2\)

\(=\left(\dfrac{3}{7}\right)^2\cdot49^2\)

\(=\left(\dfrac{3}{7}\cdot49\right)^2\)

\(=\left(\dfrac{147}{7}\right)^2\)

\(=21^2\)

\(=441\)

5) \(\left(-11\right)^{12}\cdot\left(\dfrac{4}{11}\right)^6\)

\(=\left[\left(-11\right)^2\right]^6\cdot\left(\dfrac{4}{11}\right)^6\)

\(=121^6\cdot\left(\dfrac{4}{11}\right)^6\)

\(=\left(121\cdot\dfrac{4}{11}\right)^6\)

\(=44^6\)

6) \(6^8\cdot\left(\dfrac{5}{7}\right)^7\)

\(=6^8\cdot\dfrac{5^7}{6^7}\)

\(=\dfrac{6^8\cdot5^7}{6^7}\)

\(=6\cdot5^7\)

\(=469750\)

\(\left(\dfrac{3}{7}\right)^2\cdot\left(-7\right)^4=\dfrac{9}{49}\cdot49^2=9\cdot49=441\)

\(\left(-11\right)^{12}\cdot\left(\dfrac{4}{11}\right)^4=11^{12}\cdot\dfrac{4^4}{11^4}=11^8\cdot4^4=54875873536\) 

\(\left(-6\right)^8\cdot\left(\dfrac{5}{6}\right)^7=6^8\cdot\dfrac{5^7}{6^7}=6\cdot5^7=469750\)

Bài 1

\(d,66\cdot25+5\cdot66+66\cdot14+33\cdot66\)

\(=66\left(25+5+14+33\right)\)

\(=66\cdot77\)

\(=5082\)

Hình như chép sai đề vì không thể nào tính nhanh đc

Bài 2

\(7+\left(63:x-11\right)\cdot23=237\)

\(\Leftrightarrow\left(63:x-11\right)\cdot23=230\)

\(\Leftrightarrow63:X-11=10\)

\(\Leftrightarrow63:x=21\)

\(\Leftrightarrow x=3\)

Bài 1 :

\(d,66.25+5.66+66.14+33.66\)

\(=66.\left(25+5+14+33\right)\)

\(=66.77\)

\(=5082\)

Bài 2 :

\(7+\left(63:x-11\right).23=237\)

\(\Leftrightarrow\left(63:x-11\right).23=230\)

\(\Leftrightarrow63:x-11=10\)

\(\Leftrightarrow63:x=21\)

\(\Leftrightarrow x=3\)

Vậy x = 3 .

Học tốt nhé

66.25+5.66+66.14+33.66

=66.(25+5+14+33)

=66.77

=5082

7+(63:x-11).23=237

(63:x-11).23=237-7

(63:x-11).23=230

(63:x-11)=230:23

(63:x-11)=10

63:x=10+11

63:x=21

x=63:21

x=3

vậy x=3

3/-4+2/7+-1/4+5/7+21/22.66/7

=(-3/4+-1/4)+(2/7+5/7)+9

=-1+1+9

=9

Chúc bạn học tốt!

3/-4+2/7+-1/4+5/7+21/22.66/7

=(-3/4+-1/4)+(2/7+5/7)+9

=-1+1+9

=9

1x9x8x5x3x7x2x66+9=997929

=997929 nha nastru

1x9x8x5x3x7x2x66+9

=72x5x3x7x2x66+9

=72x3x7x5x2x66+9

=72x21x10x66+9

=1512x66x10+9

=99792x10+9

=14998

chúc bạn hok tốt

14998

14998

6: =>x=9/10+1/5=9/10+2/10=11/10

7: =>x=3/8-5/12=36/96-40/96=-1/24

8: =>x=7/6-5/4=14/12-15/12=-1/12

9: =>x=1/35+2/7=1/35+10/35=11/35

10: =>x=2/7-7/10=20/70-49/70=-29/70

1, \(x=-\dfrac{5}{3}-\dfrac{1}{2}=-\dfrac{10}{6}-\dfrac{3}{6}=-\dfrac{13}{6}\)

2, \(x=\dfrac{1}{3}-\dfrac{3}{5}=\dfrac{5-9}{15}=-\dfrac{4}{15}\)

4, \(x=-\dfrac{7}{9}+\dfrac{4}{3}=\dfrac{-7+12}{9}=\dfrac{5}{9}\)

5, \(x=\dfrac{5}{6}-\dfrac{7}{3}=\dfrac{5-14}{6}=-\dfrac{9}{6}=-\dfrac{3}{2}\)

6, \(x=\dfrac{9}{10}+\dfrac{1}{5}=\dfrac{9+2}{10}=\dfrac{11}{10}\)

7, \(x=\dfrac{3}{8}-\dfrac{5}{12}=\dfrac{9-10}{12}=-\dfrac{1}{12}\)

8, \(x=\dfrac{7}{6}-\dfrac{5}{4}=\dfrac{14-15}{12}=-\dfrac{1}{12}\)

9, \(x=\dfrac{1}{35}+\dfrac{2}{7}=\dfrac{1+10}{35}=\dfrac{11}{35}\)

10, \(x=-\dfrac{7}{10}+\dfrac{2}{7}=\dfrac{-49+20}{70}=\dfrac{-29}{70}\)

\(=\dfrac{1}{5}-\dfrac{1}{6}+\dfrac{1}{6}-\dfrac{1}{11}+\dfrac{1}{11}-\dfrac{1}{13}+\dfrac{1}{13}-\dfrac{1}{20}=\dfrac{1}{5}-\dfrac{1}{20}=\dfrac{3}{20}\)

Zui lòng chia nhỏ

1: =>x=-5/3-1/2=-13/6

2: =>x=1/3-3/5=-4/15

4: =>x=-7/9+4/3=-7/9+12/9=5/9

5: =>x=5/6-7/3=5/6-14/6=-9/6=-3/2

6: =>x=9/10+1/5=11/10

7: =>x=3/8-5/12=36/96-40/96=-1/24

8: Đề sai rồi bạn