a) Ta có: \(\frac{3x+2}{5x+7}=\frac{3x-1}{5x+1}\)

\(\Leftrightarrow\left(3x+2\right)\left(5x+1\right)=\left(5x+7\right)\left(3x-1\right)\)

\(\Leftrightarrow3x\left(5x+1\right)+2\left(5x+1\right)=5x\left(3x-1\right)+7\left(3x-1\right)\)

\(\Leftrightarrow15x^2+3x+10x+2=15x^2-5x+21x-7\)

\(\Leftrightarrow15x^2-15x^2+3x+10x+5x-21x=-7-2\)

\(\Leftrightarrow-3x=-9\)

\(\Leftrightarrow x=3\)

Vậy x = 3

b) Ta có: \(\frac{x+1}{2x+1}=\frac{0,5x+2}{x+3}\Leftrightarrow\left(x+1\right)\left(x+3\right)=\left(2x+1\right)\left(0,5x+2\right)\)

                            \(\Leftrightarrow x\left(x+3\right)+\left(x+3\right)=2x\left(0,5x+2\right)+\left(0,5x+2\right)\)

                             \(\Leftrightarrow x^2+3x+x+3=x^2+4x+0,5x+2\)

                              \(\Leftrightarrow x^2-x^2+3x+x-4x-0,5x=2-3\)

                             \(\Leftrightarrow-0,5x=-1\Leftrightarrow x=2\)

Vậy x = 2

bài này sử dụng tích chéo nha bạn

z cau lamđi

(5x-2)(3x+1)+(7-15x)(x+3)=-20

<=> 15x²+5x-6x-2+7x+21-15x²-45x+20=0

<=>39-39x=0

<=>39(1-x)=0

<=>1-x=0

=>x=1

(5x-2)(3x+1)+(7-15x)(x+3)=-20

=>\(15x^2-6x+5x-2+7x-15^2+21-45x=-20\)

=>\(-39x+19=-20\)

=>\(-39x=-39\)

=>\(x=1\)

vậy x=1

(5x-2)(3x+1)+(7-15x)(x+3)=-20

<=>\(15x^2+5x-6x-2+7x-15x^2+21-45x=-20\)

<=>\(-39x+19=0\)

<=>\(-39x=-19\)

<=>\(x=\dfrac{19}{39}\)

Vậy \(x=\dfrac{19}{39}\)

\(A\left(x\right)=8-5x+3x^2-15-3x+16=3x^2-8x+9\)

\(B\left(x\right)=5x-2x^2+4x-1-x^2-3x=-3x^2+6x-1\)

\(C\left(x\right)=B\left(x\right)-A\left(x\right)=\left(-3x^2+6x-1\right)-\left(3x^2-8x+9\right)\)

\(C\left(x\right)=-6x^2+14x-10\)

3x^2-5x+2=0

<=>3x²-3x-2x+2=0

<=>3x.(x-1)-2.(x-1)=0

<=>(x-1)(3x-2)=0

<=>x-1=0 hoặc 3x-2=0

<=>x=1 hoặc 3x=2

<=>x=1 hoặc x=2/3

Đăng từng câu đio

,(8x-3).(3x+2)-(4x+7).(x+4)=(2x+1).(5x-1)-33 đúng không bạn

a,

x-43+7=49-(50+3)

<=>x-36=49-53

<=>x-36=-4

<=>x=-4+36

<=>x=32

b

-(x-16)+70=45

<=>-x+16+70=45

<=>-x+86=45

<=>x=86-45

<=>x=41

Bài 2

a.,

2x-(-60)=3x-18

<=>2x+60=3x-18

<=>3x-2x=60+18

<=>x=78

b,

-45-5x=10-4x

<=>-4x+5x=-45-10

<=>x=-55

Nếu thấy bài làm của mình đúng thì tick nha bạn,mình xin chân thành cảm ơn.

a) x-  43 + 7 = 49 - (50 + 3)

x - 36 = -4

x = -4 + 36

x = 32

b) -(x - 16) + 70 = 45

-(x - 16) = -15

x - 16 = 15

x = 31

Bài 2:

2x - (-60) = 3x - 18

2x + 60 = 3x - 18

3x - 2x = 60 + 18

x = 78

b) -4- 5x = 10 - 4x

5x - 4x = -4 - 10

x = -14