\(\frac{2^5.7+2^5}{2^5.5^2-2^5.3}=\frac{2^5.\left(7+1\right)}{2^5.\left(5^2-3\right)}=\frac{8}{25-3}=\frac{8}{22}=\frac{4}{11}\)

\(\frac{3^4.5-3^6}{3^4.13+3^4}=\frac{3^4.\left(5-3^2\right)}{3^4.\left(13+1\right)}=\frac{5-9}{14}=\frac{-4}{14}=\frac{-2}{7}\)

\(\frac{-2}{7}=\frac{-22}{77}\)

\(\frac{4}{11}=\frac{28}{77}\)

= 28/77 

1)a)x-7=0 khi x=7

     x+3=0 khi x=-3

Ta có bảng xét dấu sau:

7290 câu b tẹo nữa tính tiếp

a) \(\frac{2^3.3^4}{2^2.3^2.5}=\frac{2.3^2}{1.1.5}=\frac{18}{5}\)

b) \(\frac{2^4.5^2.11^2.7}{2^3.5^3.7^2.11}=\frac{2.1.11.1}{1.5.7.1}=\frac{22}{35}\)

Bài 1: 

  a) 6/2 x+ 1 = 2/7 

      6/2 x     = 2/7  - 1

     6/2 x      = 2/7  - 7/7

     6/2 x     =  -5/7

          x     = - 5/7 : 6/2

         x     = - 5/7 . 2/6

        x     = -5/21

Ủng hộ nha! :)      

BÀI 1 a 6/2x+1=2/7

6/2x=2/7-1

6/2x=-5/7

6*7=5*2x

42=5*2x

42/5=2x

x=42/5:2

x=21/5

a) \(\frac{2^3.3^4}{2^2.3^2.5}=\frac{2.3^2}{5}\)

b) \(\frac{2^4.5^2.11^2.7}{2^3.5^3.7^2.11}=\frac{2.11}{5.7}\)

c) \(\frac{121.75.130.69}{39.60.11.198}=\frac{11^2.3.5^2.2.5.13.23.3}{13.3.2^3.3.5.11.11.3^2.2}\)

\(=\frac{11^2.3^2.5^3.2.13.23}{13.3^4.2^4.5.11^2}=\frac{5^2.23}{3^2.2^3}\)

a,\(\frac{2^3.3^4}{2^2.3^2.5}=\frac{2^2.2.3^2.3^2}{2^2.3^2.5}\)\(=\frac{2.3^2}{5}\)

b,\(\frac{2^4.5^2.11^2.7}{2^3.5^3.7^2.11}=\frac{2^3.2.5^2.11.11.7}{2^3.5^2.5.7.7.11}=\frac{2.11}{5.7}\)

Bài 1 câu a:

1/-8 + -5/8

= -1/8 - 5/8

= -6/8

= -3/4

Câu b:

-1/21 + -1/28

= -4/84 - 3/84

= - 7/854

Câu c:

-5/9 + 8/15 + -2/11 + 4/-9 + 7/15

= (8/15+ 7/15) - (5/9 + 4/9) - 2/11

= 1 - 1 - 2/11

= 0 - 2/11

= - 2/11

Câu d:

-25/-75 + 17/34 + 121/- 132

= 1/3 + 1/2 - 11/12

= 4/12 + 6/12 - 11/12

= 10/12 - 11/12

= - 1/12

Bài 2a:

51/23 = 5151/2323 = 515151/232323

\(\frac{5151}{2323}\) = \(\frac{5151:101}{2323:101}\) = \(\frac{51}{23}\) (1)

\(\frac{515151}{232323}\) = \(\frac{515151:10101}{232323:10101}\) = \(\frac{51}{23}\) (2)

Từ (1) và (2) ta có:

\(\frac{51}{23}=\frac{5151}{2323}=\frac{515151}{232323}\) (đpcm)

a)338800/539000=22/35

b)60/20=1/3