a)100-7.[x-5]=58

          7.[x-5]=100-58=42

               x-5=42:7=6

                  x=6+5

                  x=11

b)12.[x-1]:3=4³+2³

   12 [x-1]:3=64+8

   12.[x-1]:3=72

        [x-1]:3=72:12=6

           [x-1]=6.3=18

                x=18-1

                x=17

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a) 3/4 + 1/4: x = -3 

             1/4: x = -3 - 3/4

             1/4 : x = -15/4

                      x  = 1/4 : -15/4

                    x    = -1/15 

Bài 3 

a) x^3 = x^5 => x^5 - x^3 =0 => x^3( x^2 - 1 ) = 0 

=> x^3(x - 1 ) ( x+ 1 )= 0

=> x^3 = 0 hoặc x - 1 = 0 hoặc x + 1 = 0 

=> x = 0 hoặc x = 1 hoặc x -1 

tick đúng cho mình nha 

2)x=1/15

3)a)x=0            x=1

b)x=6

a. x mũ 2 - 2x + 1 = 25 

= x^2 + 2.x.1 + 1^2

= ( x + 1 ) ^2

ko bt có đúng ko nữa, mấy câu kia tui ko bt lm

Sos

hahaha

\(f\left(x\right)=-3x^2+x-1+x^4-x^3-x^2+3x^4+2x^3\)

\(f\left(x\right)=\left(x^4+3x^4\right)-\left(x^3-2x^3\right)-\left(3x^2+x^2\right)+x-1\)

\(f\left(x\right)=4x^4+x^3-4x^2+x-1\)

\(g\left(x\right)=x^4+x^2-x^3+x-5+5x^3-x^2-3x^4\)

\(g\left(x\right)=\left(x^4-3x^4\right)+\left(5x^3-x^3\right)+\left(x^2-x^2\right)+x-5\)

\(g\left(x\right)=-2x^4+4x^3+x-5\)

`@` `\text {Ans}`

`\downarrow`

`a,`

\(f(x) -3x^2 + x - 1 + x^4 - x^3 - x^2 + 3x^4 + 2x^3\)

`= (x^4 +3x^4) + (-x^3 +2x^3) + (-3x^2 - x^2) + x - 1`

`= 4x^4 + x^3 -4x^2 + x -1`

\(g(x) = x^4 + x^2 - x^3 + x - 5 + 5x^3 - x^2 - 3x^4\)

`= (x^4-3x^4) + (-x^3+5x^3) + (x^2 - x^2) + x -5`

`= -2x^4 + 4x^3 +x - 5`

M  = 4⁰ + 4¹ + 4² + 4³ + ... + 4⁹⁸

=> 4M = 4¹ + 4² + 4³ + 4⁴ + ... + 4⁹⁹

Khi đó 4M - M = (4¹ + 4² + 4³ + 4⁴ + ... + 4⁹⁹) - (4⁰ + 4¹ + 4² + 4³ + ... + 4⁹⁸)

=> 3M = 4⁹⁹ - 4⁰ = 4⁹⁹ - 1

Khi đó 2^x = 3M + 1

<=> 2^x = 4⁹⁹ - 1 + 1

=> 2^x = 4⁹⁹

=> 2^x = (2²)⁹⁹

=> 2^x = 2^2.99

=> 2^x = 2¹⁹⁸

=> x = 198

Vậy x = 198

M = 4⁰ + 4¹ + 4² + 4³ + ... + 4⁹⁸

4M = 4( 4⁰ + 4¹ + 4² + 4³ + ... + 4⁹⁸ )

      = 4¹ + 4² + 4³ + 4⁴ + ... + 4⁹⁹

=> 3M = 4M - M

           = 4¹ + 4² + 4³ + 4⁴ + ... + 4⁹⁹ - ( 4⁰ + 4¹ + 4² + 4³ + ... + 4⁹⁸ )

           = 4¹ + 4² + 4³ + 4⁴ + ... + 4⁹⁹ - 4⁰ - 4¹ - 4² - 4³ - ... - 4⁹⁸ 

           = 4⁹⁹ - 1

2^x = 3M + 1

<=> 2^x = 4⁹⁹ - 1 + 1

<=> 2^x = 4⁹⁹ 

<=> 2^x = (2²)⁹⁹ = 2¹⁹⁸

<=> x = 198

\(a.x-143=57\)

\(x=200\)

\(b.\left(8x-12\right):4=3^3\)

\(8x-12=27.4\)

\(8x-12=108\)

\(8x=120\)

\(x=15\)

\(d.10+2x=4^2\)

\(2x=16-10\)

\(2x=6\)

\(x=3\)

a) 716-(x-143)=659

<=>x-143=57

<=>x=57+143

<=>x=200

b) [(8x-12):4].3³=3⁶

<=>(8x-12):4=3³

<=>8x-12=27.4

<=>8x-12=108

<=>8x=120

<=>x=5

c) -2<|x|≤1, x thuộc Z

Vì -2<|x|≤1

=>|x| thuộc {-1;0;1}

+)Với |x|=-1=>Vô lí

+)Với |x|=0=>x=0(tm)

+)Với |x|=1=>x=-1;1(tm) 

Vậy x thuộc {-1;1;0}

d) 10+2x=4⁵:4³

<=>10+2x=16

<=>2x=6

<=>x=3

e) 4^x+1+4⁰=65

<=>4^x+1+1=65

<=>4^x+1=64

<=>4^x+1=4³

<=>x+1=3

<=>x=2

g) 96-2(x+1)=-42

<=>2(x+1)=96+42

<=>2(x+1)=138

<=>x+1=69

<=>x=68

h) 4x-20=2⁵:2²

<=>4x-20=2³

<=>4x=8+20

<=>4x=28

<=>x=7

k) 8x-75=5x+21

<=>8x-5x=75+21

<=>3x=96

<=>x=32

i) [(8x-14):2-2].31=341

<=>(8x-14):2-2=11

<=>(8x-14):2=13

<=>8x-14=26

<=>8x=40

<=>x=5

Bài 8:

a: \(\left(\dfrac{2}{5}+\dfrac{3}{4}\right)^2=\left(\dfrac{8+15}{20}\right)^2=\left(\dfrac{23}{20}\right)^2=\dfrac{529}{400}\)

b: \(\left(\dfrac{5}{4}-\dfrac{1}{6}\right)^2=\left(\dfrac{15}{12}-\dfrac{2}{12}\right)^2=\left(\dfrac{13}{12}\right)^2=\dfrac{169}{144}\)