1)6x-8=3x+1

6x-3x=1+8

3x=9

x=3

Vậy x=3

2: 12-10x=25-30x

=>20x=13

=>x=13/20

3: \(3\left(2x+3\right)-2\left(4x-5\right)=10x+21\)

=>6x+9-8x+10=10x+21

=>10x+21=-2x+19

=>12x=-2

=>x=-1/6

4: \(\Leftrightarrow25x-15-6x+12=11-5x\)

=>19x-3=11-5x

=>24x=14

=>x=7/12

5: \(\Leftrightarrow8-12x-5+10x=4-6x\)

=>4-6x=-2x+3

=>-4x=-1

=>x=1/4

6: \(\Leftrightarrow32x-24-6+9x=13-40x\)

=>41x-30=13-40x

=>81x=43

=>x=43/81

7: \(\Leftrightarrow10x-5+20x=5x-11\)

=>30x-5=5x-11

=>25x=-6

=>x=-6/25

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?

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

a: \(=8x^3-10x^5+10x^5-5x^3=3x^3\)

b: \(=x^3-2x^2+4x-2x^2+4x-8+x^2+2x-4x-8\)

\(=x^3-3x^2+4x-16\)

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

\(\Rightarrow\left(2x+3\right)\left(10x+2\right)=\left(5x+2\right)\left(4x+5\right)\)

\(\Rightarrow20x^2+4x+30x+6=20x^2+25x+8x+10\)

\(\Rightarrow x=4\)

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

=> (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