a, A =  2 2 . 5 2 - 3 2 - 10 = 81 =  3 4 = 9 2

b, B =  3 3 . 3 2 + 2 2 + 3 2 = 256 =  16 2 = 2 8 = 4 4

c, C =  5 . 4 3 + 2 4 . 5 = 400 =  20 2

d, D =  5 3 + 6 3 + 7 3 + 79 . 2 2 = 1000 =  10 3

a)  A = 2 5 . 5 2 - 3 2 - 10 = 81 = 3 4 ( = 9 2 ) .

b)  B = 3 3 . 3 2 + 2 2 + 3 2 = 256 = 16 2 ( = 2 8 = 4 4 ) .

c)  C = 5 . 4 3 + 2 4 . 5 = 400 = 20 2

d)  D = 5 3 + 6 3 + 7 3 + 7 9 . 2 2 = 1000 = 10 3 .

a, \(15:\left(x+2\right)=3\Leftrightarrow x+2=3\Leftrightarrow x=1\)

b, \(20:\left(x+1\right)=2\Leftrightarrow x+1=10\Leftrightarrow x=9\)

c, \(240:\left(x-5\right)=2^2.5^2-20=80\Leftrightarrow x-5=3\Leftrightarrow x=8\)

d, \(96-3\left(x+1\right)=42\Leftrightarrow3\left(x+1\right)=54\Leftrightarrow x+1=18\Leftrightarrow x=17\)

a) 15 : (x + 2) = 3

x + 2 = 15 : 3

x + 2 = 5

x = 5 – 2 = 3

b) 20 : (1 + x) = 2

1 + x = 20 : 2

1 + x = 10

x = 10 – 1 = 9

c) 240 : (x – 5) = 2².5² – 20

240 : (x – 5) = 4.25 – 20

240 : (x - 5) = 100 – 20

240 : (x - 5) = 80

x – 5 = 240 : 80

x – 5 = 3

x = 3 + 5 = 8

d) 96 - 3(x + 1) = 42

3(x + 1) = 96 – 42

3(x + 1) = 54

x + 1 = 54 : 3

x + 1 = 18

x = 18 – 1

x = 17

\(15\div\left(x+2\right)=3\)                                           \(20\div\left(1+x\right)=2\)

\(x+2=15\div3\)                                               \(1+x=20\div2\)

\(x+2=5\)                                                       1+x=10

x = 5 - 2                                                           x=9

x = 3

\(240\div\left(x-5\right)=2^2\cdot5^2-20\)                                \(96-3\left(x+1\right)=42\)

\(240\div\left(x-5\right)=80\)                                              \(3\left(x+1\right)=96-42\)

\(x-5=240\div80\)                                                 \(3\left(x+1\right)=54\)

x-5=3                                                                    \(x+1=54\div3\)

x=8                                                                        x+1=18

                                                                              x=17

`240:(x–5)=22xx52–20`

`240:(x–5)=1144-20`

`240:(x-5)=1124`

`x-5=240:1124`

`x-5=60/281`

`x=60/281 + 5`

`x=1465/281`

240:(x - 5)=1144 - 20

240:(x - 5)=1124

         x - 5 =240:1124

         x - 5 = 60/281

              x = 60/281 + 1405/281

              x = 1465/281

\(240:\left(x-5\right)=22\cdot52-20\)

\(\Leftrightarrow240:\left(x-5\right)=1124\)

\(\Leftrightarrow x-5=\dfrac{60}{281}\)

hay \(x=\dfrac{1465}{281}\)

\(240:\left(x-5\right)=22.52-20\)

\(\Rightarrow240:\left(x-5\right)=1144-20\)

\(\Rightarrow240:\left(x-5\right)=1124\)

\(\Rightarrow x-5=\dfrac{60}{281}\)

\(\Rightarrow x=\dfrac{1465}{281}\)

\(\Leftrightarrow240:\left(x-5\right)=1124\\ \Leftrightarrow x-5=\dfrac{60}{281}\Leftrightarrow x=\dfrac{1465}{281}\)

5^2x-3-2.5² =5² . 3

⇔5^2x-1.5²-2.5²=5².3

⇔5².(5^2x-1-2)=5².3

⇔5^2x-1-2=3

⇔5^2x-1=5

⇔2x-1=1

⇔2x=2

⇔x=1

vay x=1

af nham mink sai :>
 

5²ˣ⁻³ - 2.5² = 5².3

5²ˣ⁻³ - 2.25 = 25.3

5²ˣ⁻³ - 50 = 75

5²ˣ⁻³ = 75 + 50

5²ˣ⁻³ = 125

5²ˣ⁻³ = 5³

2x - 3 = 3

2x = 3 + 3

2x = 6

x = 6 : 2

x = 3

alo ạ

a) 27.75 + 25.27 - 150.2023⁰

= 27.(75 + 25) - 150.1

= 27.100 - 150

= 2700 - 150

= 2550

b) Sửa đề:

3ˣ + 3ˣ⁺¹ + 16.4 = 2².5²

3ˣ.(1 + 3) + 64 = 4.25

3ˣ.4 + 64 = 100

3ˣ.4 = 100 - 64

3ˣ.4 = 36

3ˣ = 36 : 4

3ˣ = 9

3ˣ = 3²

x = 2

Bài 4:

\(a,2^{30}=\left(2^3\right)^{10}=8^{10};3^{20}=\left(3^2\right)^{10}=9^{10}\\ Vì:8^{10}< 9^{10}\left(Vì:8< 9\right)\Rightarrow2^{30}< 3^{20}\\ b,9^{10}.27^5=\left(3^2\right)^{10}.\left(3^3\right)^5=3^{20}.3^{15}=3^{35}\\ 243^7=\left(3^5\right)^7=3^{35}\\ Vì:3^{35}=3^{35}\Rightarrow243^7=9^{10}.27^5\)

Bài 5:

100< 5^2x-3 < 59

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