a) \(\frac{x}{2}-\frac{11}{5}=\frac{7}{8}.\frac{64}{49}\)

\(\frac{x}{2}-\frac{11}{5}=\frac{8}{7}\)

\(\frac{x}{2}=\frac{8}{7}+\frac{11}{5}\)

\(\frac{x}{2}=\frac{117}{35}\)

\(x=\frac{117}{35}\times2\)

\(x=\frac{234}{35}\)

b) \(\frac{y}{5}+\frac{9}{2}=\frac{6}{7}.\frac{36}{49}\)

\(\frac{y}{5}+\frac{9}{2}=\frac{216}{343}\)

\(\frac{y}{5}=\frac{216}{343}-\frac{9}{2}\)

\(\frac{y}{5}=\frac{-2655}{686}\)

\(y=\frac{-2655}{686}.5\)

\(y=\frac{-13275}{686}\)

ra kết quả to quá bn ạ! Bn xem lại giúp mk nha!

\(\frac{3}{2}x-\frac{11}{5}=\frac{7}{8}.\frac{64}{49}\)

\(\frac{3}{2}x-\frac{11}{5}=\frac{8}{7}\)

\(\frac{3}{2}x=\frac{8}{7}+\frac{11}{5}=\frac{117}{35}\)

\(x=\frac{117}{35}:\frac{3}{2}=\frac{78}{35}\)

\(\frac{3}{2}x-\frac{11}{5}=\frac{7}{8}.\frac{64}{49}\) 

\(\frac{3}{2}x-\frac{11}{5}=\frac{8}{7}\)

\(\frac{3}{2}x=\frac{8}{7}+\frac{11}{5}\)

\(\frac{3}{2}x=\frac{117}{35}\)

\(x=\frac{117}{35}:\frac{3}{2}\)

\(x=\frac{78}{35}\)

\(\frac{x}{2}-\frac{11}{5}\)\(=\frac{7}{8}\times\frac{64}{49}\) ⇒\(\frac{x}{2}\) \(-\frac{11}{5}\)\(=\)\(\frac{8}{7}\) ⇒\(\frac{x}{2}=\frac{8}{7}+\frac{11}{5}\) ⇒\(\frac{x}{2}=\frac{117}{35}\) ⇒\(x=\frac{117}{35}\times2=\frac{234}{35}\)

\(\frac{x}{2}-\frac{11}{5}=\frac{7}{8}.\frac{64}{49}\)

=>

a) \(\frac{X}{2}-\frac{11}{5}=\frac{7}{8}\cdot\frac{64}{49}\)

\(\Rightarrow\frac{x}{2}-\frac{11}{5}=\frac{8}{7}\)

\(\Rightarrow\frac{x}{2}=\frac{8}{7}+\frac{11}{5}\)

\(\Rightarrow\frac{x}{2}=\frac{117}{35}\)\(\Rightarrow x=\frac{117}{35}\cdot2=\frac{234}{35}\)

b)\(\frac{x}{5}+\frac{9}{2}=\frac{6}{7}\cdot\frac{36}{49}\)

\(\Rightarrow\frac{x}{5}+\frac{9}{2}=\frac{216}{343}\)

\(\Rightarrow\frac{x}{5}=\frac{216}{343}-\frac{9}{2}=\frac{-2655}{686}\)

\(\Rightarrow x=\frac{-2655}{686}\cdot5=\frac{-13275}{686}\)

        x/2 - 11/5 = 7/8 . 64/49

        x/2 - 11/5 = 8/7

        x/2          =8/7 + 11/5

        x/2          = 117/35

        x             = 2.117/35 ( tính chất phân số bằng nhau)

        x             = 234/35 

       x/5 + 9/2 = 6/7 . 36/49

       x/5 + 9/2 = 216/343

        x/5         = 216/343 - 9/2

        x/5         = -2655/686

        x           = 5.(-2655)/686

        x           = -13275/686 

tui trả lời trước mà ko tk

\(\frac{x}{2}-\frac{11}{5}=\frac{7}{5}.\frac{64}{49}\)

\(\frac{x}{2}-\frac{11}{5}=\frac{64}{35}\)

\(\frac{x}{2}=\frac{64}{35}+\frac{11}{5}\)

\(\frac{x}{2}=\frac{141}{35}\)

\(\Leftrightarrow x.35=2.141\)

\(\Leftrightarrow x.35=282\)

\(\Leftrightarrow x=282:35\)

\(\Leftrightarrow x=\frac{282}{35}\)

x/2 - 11/5 = 7/5.64/49

=> x/2 - 11/5 = 64/35

=> x/2 = 64/35 + 11/5

=> x/2 = 141/35

=> 35x = 2.141

=> 35x = 282

=> x = 282 : 35 = 282/35

a, 27³ : 3⁵  =  ( 3³)³ : 3⁵ = 3⁹ : 3⁵ = 3⁴

b, 7² . 343 . 49³⁰ = 7². 7³.(7²)³  = 7¹¹

c, 625 : 5³ = 5⁴ : 5³ =  5

d, 1 000 000 : 10³ = 10⁶ . 10³ = 10³

e, 11⁵ : 121= 11⁵ : 11² = 11³

f, 8⁷ : 64 :8 = 8⁷ : 8² : 8¹ = 8⁴

i, 1024 . 16 : 2⁶  = 2¹⁰ . 2³ : 2⁶ = 2⁷

B2:

 số chính phương là:

4 ; 121 ; 196 ; 225.

Bài 2 :

Số chính phương là :

\(4=2^2\)

\(121=11^2\)

\(196=14^2\)

\(225=25^2\)

a) 89-(73-x) = 20

=> 73+x =89-20

=> 73+x=69

=> x=69-73

=> x=-4

b) (x+7)-25=13

=> x+7=13+25

=> x+7=38

=> x=38-7

=> x=31

c) 98-(x+4)=20

=> x+4=98-20

=> x+4=78

=> x=78-4

=> x=73

d) 140:(x-8)=7

=> x-8=140:7

=> x-8=20

=> x=20+8

=> x=28

e) 4(x+41)=400

=> x+41=400:4

=> x+41=100

=> x=100-41

=> x=59

f) x-[42+(-28)]=-8

=> x-14=-8

=> x=-8+14

=> x=6

g) x+5=20-(12-7)

=> x+5=20-5

=> x+5=15

=> x=15-5

=> x=10

h) \(x-11=2.2^3+20:5\)

=> x-11=2.8+4

=> x-11=16+4

=> x-11=20

=> x=20+11

=> x=31

i) \(4\left(x-3\right)=7^2-1^3\)

=> 4(x-3)=49-1

=> 4(x-3)=48

=> x-3=48:4

=> x-3=12

=> x=12+3

=> x=15