2x+3/5x+2 = 4x+5/10x+2

<=> (2x+3)(10x+2)=(5x+2)(4x+5)

<=>2x(10x+2)+3(10x+2)= 5x(4x+5)+2(4x+5)

<=> 20x^2+4x+20x+6 = 20x^2+25x+9x+10

<=> 20x^2+4x+20x+6 - (20x^2+25x+9x+10)=0 => 20x^2+24x+6-(20x^2+34x+10)=0

                                                                  <=>   -10x-4=0

                                                                 <=>-10x=4

                                                                  <=> x= -4/10

2x+3/5x+2=4x+5/10x+2

=> (2x+3)(10x+2)=(5x+2)(4x+5)

=> 20x^2+4x+30x+6=10x^2+25x+8x+10 ( Vì cả hai vế đều có 10x^2 nên ta xóa đi )

=> 34x+6=33x+10

=> 34x-33x=-6+10

=> x=4

x⁴+5x²-9x +3

Tìm x?

\(\frac{2x+3}{5x+2}=\frac{4x+5}{10x+2}\)

=> (2x + 3)(10x + 2) = (5x + 2)(4x + 5)

=> 20x² + 4x + 30x + 6 = 20x² + 25x + 8x + 10

=> 34x + 6 = 33x + 10 (bớt 2 vế đi 20x²)

=> x = 4

=>(2x+3).(10x+2)=(5x+2).(4x+5)

=>(2x.10x)+(2x.2)+(3.10x)+(3.2)=(5x.4x)+(5x.5)+(2.4x)+(2.5)

=>20x²+4x+30x+6=20x²+25x+8x+10

=>20x²-20x²+4x-8x+30x-25x=10-6

=>0+4x-8x+30x-25x=4

=>-4x+30x-25x=4

=>26x-25x=4

=>x=4

B)=>(3x-1).(5x-34)=(40-5x).(25-3x)

=>15x²-102x-5x+34=1000-120x-125x+15x²

=>15x²-107x+34=1000-245x+15x²

=>15x²-15x²-107x+245x=1000-34

=>0-107x+245x=966

=>138x=966

=>x=7

A,=>(2x+3).(10x+2)=(5x+2).(4x+5)

=>(2x.10x)+(2x.2)+(3.10x)+(3.2)=(5x.4x)+(5x.5)+(2.4x)+(2.5)

=>20x2+4x+30x+6=20x2+25x+8x+10

=>20x2-20x2+4x-8x+30x-25x=10-6

=>0+4x-8x+30x-25x=4

=>-4x+30x-25x=4

=>26x-25x=4

=>x=4

`@` `\text {Ans}`

`\downarrow`

`a)`

`3x(4x-1) - 2x(6x-3) = 30`

`=> 12x^2 - 3x - 12x^2 + 6x = 30`

`=> 3x = 30`

`=> x = 30 \div 3`

`=> x=10`

Vậy, `x=10`

`b)`

`2x(3-2x) + 2x(2x-1) = 15`

`=> 6x- 4x^2 + 4x^2 - 2x = 15`

`=> 4x = 15`

`=> x = 15/4`

Vậy, `x=15/4`

`c)`

`(5x-2)(4x-1) + (10x+3)(2x-1) = 1`

`=> 5x(4x-1) - 2(4x-1) + 10x(2x-1) + 3(2x-1)=1`

`=> 20x^2-5x - 8x + 2 + 20x^2 - 10x +6x - 3 =1`

`=> 40x^2 -17x - 1 = 1`

`d)`

`(x+2)(x+2)-(x-3)(x+1)=9`

`=> x^2 + 2x + 2x + 4 - x^2 - x + 3x + 3=9`

`=> 6x + 7 =9`

`=> 6x = 2`

`=> x=2/6 =1/3`

Vậy, `x=1/3`

`e)`

`(4x+1)(6x-3) = 7 + (3x-2)(8x+9)`

`=> 24x^2 - 12x + 6x - 3 = 7 + (3x-2)(8x+9)`

`=> 24x^2 - 12x + 6x - 3 = 7 + 24x^2 +11x - 18`

`=> 24x^2 - 6x - 3 = 24x^2 + 18x -11`

`=> 24x^2 - 6x - 3 - 24x^2 + 18x + 11 = 0`

`=> 12x +8 = 0`

`=> 12x = -8`

`=> x= -8/12 = -2/3`

Vậy, `x=-2/3`

`g)`

`(10x+2)(4x- 1)- (8x -3)(5x+2) =14`

`=> 40x^2 - 10x + 8x - 2 - 40x^2 - 16x + 15x + 6 = 14`

`=> -3x + 4 =14`

`=> -3x = 10`

`=> x= - 10/3`

Vậy, `x=-10/3`

Hello các bạn còn đó ko?

\(\frac{2x+3}{5x+2}=\frac{4x+5}{10x+2}\Leftrightarrow\left(2x+3\right)\left(10x+2\right)=\left(4x+5\right)\left(5x+2\right)\Leftrightarrow20x^2+34x+6=20x^2+33x+10\Leftrightarrow x=4\)

a) \(4x\left(5x+2\right)-\left(10x-3\right)\left(2x+7\right)=133\)

\(=\left(20x^2+8x\right)-\left(20x^2+64x-21\right)=133\)

\(=20x^2+8x-20x^2-64x+21=133\)

\(=-56x=112\)

\(\Leftrightarrow x=-2\)

b) \(4\left(x-1\right)\left(x+5\right)+\left(x+2\right)\left(x+5\right)=5\left(x-1\right)\left(x+2\right)\)

\(\Leftrightarrow\left(x+5\right)\left(4x-4+x+2\right)=5\left(x-1\right)\left(x+2\right)\)

\(\Leftrightarrow\left(x+5\right)\left(5x-2\right)=\left(5x-5\right)\left(x+2\right)\)

\(\Leftrightarrow5x^2+23x-10=5x^2+5x-10\)

\(\Leftrightarrow23x=5x\)

\(\Leftrightarrow18x=0\Leftrightarrow x=0\)

a) \(4x\left(5x+2\right)-\left(10x-3\right)\left(2x+7\right)=133\)

\(\Leftrightarrow20x^2+8x-\left[10x.\left(2x+7\right)-3.\left(2x+7\right)\right]=133\)

\(\Leftrightarrow20x^2+8x-\left(20x^2+70x-6x-21\right)=133\)

\(\Leftrightarrow20x^2+8x-20x^2-70x+6x+21=133\)

\(\Leftrightarrow8x-70x+6x=133-21\)

\(\Leftrightarrow-56x=112\)

\(\Leftrightarrow x=-\frac{112}{56}=-2\)

Vậy : \(x=-2\)