a) \(PT\Leftrightarrow3x-2x=2-3\Leftrightarrow x=-1\)

Vậy: \(S=\left\{-1\right\}\)

b) \(PT\Leftrightarrow-2x+3x=-7+22\Leftrightarrow x=15\)

Vậy: \(S=\left\{15\right\}\)

c) \(PT\Leftrightarrow8x-5x=3+12\Leftrightarrow3x=15\Leftrightarrow x=5\)

Vậy: \(S=\left\{5\right\}\)

d) \(PT\Leftrightarrow x+4x-2x=12+25-1\Leftrightarrow3x=36\Leftrightarrow x=12\)

Vậy: \(S=\left\{12\right\}\)

e) \(PT\Leftrightarrow x+2x+3x-3x=19+5\Leftrightarrow3x=24\Leftrightarrow x=8\)

Vậy: \(S=\left\{8\right\}\)

a)3x-2=2x-3

=>x=-1

b)7-2x=22-3x

=>x=15

c)8x-3=5x+12

=>3x=15

=>x=5

d)x-12+4x=25+2x-1

=>3x=12

=>x=4

e)x+2x+3x-19=3x+5

=>3x=24

=>x=8

a)3x-2=2x-3

=>x=-1

b)7-2x=22-3x

=>x=15

c)8x-3=5x+12

=>3x=15

=>x=5

d)x-12+4x=25+2x-1

=>3x=36

=>x=12

e)x+2x+3x-19=3x+5

=>3x=24

=>x=8

x + 2x + 3x – 19 = 3x + 5

⇔ x + 2x + 3x – 3x = 5 + 19

⇔ 3x = 24

⇔ x = 8.

Vậy phương trình có nghiệm x = 8.

Gọi a,b,c,... cho dễ nhé!

a,\(7+2x=22-3x\)

\(\Leftrightarrow2x+3x=22-7\)

\(\Leftrightarrow5x=15\)

\(\Leftrightarrow x=3\)

Vậy...

b,\(x-12+4x=25+2x-1\)

\(\Leftrightarrow x+4x-2x=25-1+12\)

\(\Leftrightarrow3x=36\)

\(\Leftrightarrow x=12\)

Vậy...

c,\(7-\left(2x+4\right)=-\left(x+4\right)\)

\(\Leftrightarrow7-2x-4=-x-4\)

\(\Leftrightarrow-2x+x=-4+4-7\)

\(\Leftrightarrow-x=-7\)

\(\Leftrightarrow x=7\)

Vậy...

d,\(8x-3=5x+12\)

\(\Leftrightarrow8x-5x=12+3\)

\(\Leftrightarrow3x=15\)

\(\Leftrightarrow x=5\)

Vậy...

e,\(x+2x+3x-19=3x+5\)

\(\Leftrightarrow x+2x+3x-3x=5+19\)

\(\Leftrightarrow3x=24\)

\(\Leftrightarrow x=8\)

Vậy...

f,\(\left(x-1\right)-\left(2x-1\right)=9-x\)

\(\Leftrightarrow x-1-2x+1=9-x\)

\(\Leftrightarrow x-2x+x=9-1+1\)

\(\Leftrightarrow0x=9\) (Vô lý)

Vậy...

a, \(7+2x=22-3x\)

\(\Rightarrow7+2x-22+3x=0\)

\(\Rightarrow5x-15=0\)

\(\Rightarrow5x=15\Rightarrow x=3\)

b, \(x-12+4x=25+2x-1\)

\(\Rightarrow3x-12-24-2x=0\)

\(\Rightarrow x-36=0\Rightarrow x=36\)

c, \(7-\left(2x+4\right)=-\left(x+4\right)\)

\(\Rightarrow7-2x-4=-x-4\)

\(\Rightarrow3-2x+x+4=0\)

\(\Rightarrow-x=-7\Rightarrow x=7\)

d, \(8x-3=5x+12\)

\(\Rightarrow8x-3-5x-12=0\)

\(\Rightarrow3x-15=0\)

\(\Rightarrow3x=15\Rightarrow x=5\)

e, \(x+2x+3x-19=3x+5\)

\(\Rightarrow6x-19-3x-5=0\)

\(\Rightarrow3x-24=0\)

\(\Rightarrow3x=24\Rightarrow x=8\)

f, \(\left(x-1\right)-\left(2x-1\right)=9-x\)

\(\Rightarrow x-1-2x+1-9+x=0\)

(hình như câu này bị sai đề rồi, bạn xem lại đề nhé)

Chúc bạn học tốt!

A,

a: \(\Leftrightarrow x^2-4-4x^2-4x-1-2x+3x^2=0\)

=>-6x-5=0

=>-6x=5

hay x=-5/6

b: \(\Leftrightarrow2x^3+8x^2+8x-8x^2-2x^3+16=0\)

=>8x+16=0

hay x=-2

c: \(\Leftrightarrow x^3-6x^2+12x-8+9x^2-1-x^3-3x^2-3x-1=0\)

=>9x-10=0

hay x=10/9

d: \(\Leftrightarrow10x-15-20x+28=19-2x^2-4x-2\)

\(\Leftrightarrow-10x+13+2x^2+4x-17=0\)

\(\Leftrightarrow2x^2-6x-4=0\)

\(\Leftrightarrow x^2-3x-2=0\)

\(\text{Δ}=\left(-3\right)^2-4\cdot1\cdot\left(-2\right)=9+8=17>0\)

Do đó: Phương trình có hai nghiệm phân biệt là:

\(\left\{{}\begin{matrix}x_1=\dfrac{3-\sqrt{17}}{2}\\x_2=\dfrac{3+\sqrt{17}}{2}\end{matrix}\right.\)

1/ \(7x-5=13-5x\)

\(\Leftrightarrow12x=18\)

\(\Leftrightarrow x=\dfrac{3}{2}\)

Vậy: \(S=\left\{\dfrac{3}{2}\right\}\)

==========

2/ \(19+3x=5-18x\)

\(\Leftrightarrow21x=-14\)

\(\Leftrightarrow x=-\dfrac{2}{3}\)

Vậy: \(S=\left\{-\dfrac{2}{3}\right\}\)

==========

3/ \(x^2+2x-4=-12+3x+x^2\)

\(\Leftrightarrow-x=-8\)

\(\Leftrightarrow x=8\)

Vậy: \(S=\left\{8\right\}\)

===========

4/ \(-\left(x+5\right)=3\left(x-5\right)\)

\(\Leftrightarrow-x-5=3x-15\)

\(\Leftrightarrow-4x=-10\)

\(\Leftrightarrow x=\dfrac{5}{2}\)

Vậy: \(S=\left\{\dfrac{5}{2}\right\}\)

==========

5/ \(3\left(x+4\right)=\left(-x+4\right)\)

\(\Leftrightarrow3x+12=-x+4\)

\(\Leftrightarrow4x=-8\)

\(\Leftrightarrow x=-2\)

Vậy: \(S=\left\{-2\right\}\)

[----------]

1. \(7x-5=13-5x\) \(\Leftrightarrow12x=18\Leftrightarrow x=\dfrac{3}{2}\)

2. \(19+3x=5-18x\Leftrightarrow21x=-14\Leftrightarrow x=-\dfrac{2}{3}\)

3. \(x^2+2x-4=-12+3x+x^2\Leftrightarrow-x=-8\Leftrightarrow x=8\)

4. \(-\left(x+5\right)=3\left(x-5\right)\Leftrightarrow-x-5=3x-15\Leftrightarrow4x=10\Leftrightarrow x=\dfrac{5}{2}\)

5. \(3\left(x+4\right)=-x+4\Leftrightarrow3x+12=-x+4\Leftrightarrow4x=-8\Leftrightarrow x=-2\)

1) Ta có: \(7x-5=13-5x\)

\(\Leftrightarrow12x=18\)

hay \(x=\dfrac{3}{2}\)

2) Ta có: \(19+3x=5-18x\)

\(\Leftrightarrow21x=-14\)

hay \(x=-\dfrac{2}{3}\)

3) Ta có: \(x^2+2x-4=x^2+3x-12\)

\(\Leftrightarrow3x-12=2x-4\)

hay x=8

4) Ta có: \(-\left(x+5\right)=3\left(x-5\right)\)

\(\Leftrightarrow-x-5-3x+15=0\)

\(\Leftrightarrow-4x=-10\)

hay \(x=\dfrac{5}{2}\)

Sửa: \(A=\left(3x+2\right)^2+\left(2x-7\right)^2-2\left(3x+2\right)\left(2x-7\right)\)

\(A=\left(3x+2\right)^2-2\left(3x+2\right)\left(2x-7\right)+\left(2x-7\right)^2\)

\(A=\left[\left(3x+2\right)-\left(2x-7\right)\right]^2\)

\(A=\left(3x+2-2x+7\right)^2\)

\(A=\left(x+9\right)^2\)

Thay \(x=-19\) vào A ta có:

\(A=\left(-19+9\right)^2=\left(-10\right)^2=100\)

Vậy: ...

a) x−12+4x=25+2x−1x−12+4x=25+2x−1

⇔5x – 12 = 2x + 24

⇔5x – 2x = 24 + 12

⇔3x = 36

⇔x = 12

Vậy phương trình có nghiệm x = 12.

b) x+2x+3x−19=3x+5x+2x+3x−19=3x+5

⇔6x – 19 = 5x +3x

⇔3x= 24

⇔x= 8

Vậy phương trình có nghiệm x = 8.

a) x−12+4x=25+2x−1x−12+4x=25+2x−1

⇔5x – 12 = 2x + 24

⇔5x – 2x = 24 + 12

⇔3x = 36

⇔x = 12

Vậy x=12 là nghiệm của phương trình

b) x+2x+3x−19=3x+5x+2x+3x−19=3x+5

⇔6x – 19 = 5x +3x

⇔3x= 24

⇔x= 8

Vậy x=8 là nghiệm của phương trình