a) Ta có: \(x^2+3x-10=0\)

\(\Leftrightarrow x^2+5x-2x-10=0\)

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

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

\(\Leftrightarrow\left[{}\begin{matrix}x+5=0\\x-2=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-5\\x=2\end{matrix}\right.\)

Vậy: S={-5;2}

b) Ta có: \(3x^2-7x+1=0\)

\(\Leftrightarrow3\left(x^2-\dfrac{7}{3}x+\dfrac{1}{3}\right)=0\)

mà 3>0

nên \(x^2-\dfrac{7}{3}x+\dfrac{1}{3}=0\)

\(\Leftrightarrow x^2-2\cdot x\cdot\dfrac{7}{6}+\dfrac{49}{36}-\dfrac{37}{36}=0\)

\(\Leftrightarrow\left(x-\dfrac{7}{6}\right)^2=\dfrac{37}{36}\)

\(\Leftrightarrow\left[{}\begin{matrix}x-\dfrac{7}{6}=\dfrac{\sqrt{37}}{6}\\x-\dfrac{7}{6}=-\dfrac{\sqrt{37}}{6}\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{\sqrt{37}+7}{6}\\x=\dfrac{-\sqrt{37}+7}{6}\end{matrix}\right.\)

Vậy: \(S=\left\{\dfrac{\sqrt{37}+7}{6};\dfrac{-\sqrt{37}+7}{6}\right\}\)

c) Ta có: \(3x^2-7x+8=0\)

\(\Leftrightarrow3\left(x^2-\dfrac{7}{3}x+\dfrac{8}{3}\right)=0\)

mà 3>0

nên \(x^2-\dfrac{7}{3}x+\dfrac{8}{3}=0\)

\(\Leftrightarrow x^2-2\cdot x\cdot\dfrac{7}{6}+\dfrac{49}{36}+\dfrac{47}{36}=0\)

\(\Leftrightarrow\left(x-\dfrac{7}{6}\right)^2=-\dfrac{47}{36}\)(vô lý)

Vậy: \(x\in\varnothing\)

ko bt

⇔(2 x ) ²+2.2 x .1+1 ²=0 ... c ,(3 x −4) ²−14(3 x −4)(6+3 x )+49(3 x +6)=16 ... ⇔9 x ²−24 x +16−126 x ²−252 x +168 x +336+147 x +294=16.

https://olm.vn/hoi-dap/detail/192758180810.html

\(-2x\left(6x-2\right)+3x\left(4x-7\right)=8\)

<=> \(-12x^2+4x+12x^2-21x=8\)

<=> \(-17x=8\)

<=> \(x=-\frac{8}{17}\)

\(\left(7x-2\right)\left(2x+3\right)-\left(3x-5\right)\left(4x+6\right)=2x^2-5\)

<=> \(14x^2+17x-6-12x^2+2x+30=2x^2-5\)

<=> \(14x^2+17x-6-12x^2+2x+30-2x^2+5=0\)

<=> \(19x+29=0\)

<=> \(19x=-29\)

<=> \(x=-\frac{29}{19}\)

Ý cuối mình k biết -22x2 là -22.2 hay -22x² nữa :)

19 22 25 28 5(3x + 2) – 4(2x +3) x*(1 + 2x) 4(1 + x) – 3(2x-5) 4x–8(6) - X) 23/ ... 2x” – 4x + 3x – 6 = 2x” – X-6 (b) (x-3) = (x-3)(x-3) (c) (2x+y)(2x–y) = x* = x* – 3x ... (x - 6)” 7 (3x + 5)(x-6) 8 (8x + 2)(3x + 4) (4x – 1)(2x – 3) 10 (2x +5)* 11 (8x – 3)(2x + ... 27 (4x + 3y)(x + y) 28 (2x + 5)(5x – 2) (4x – 3y)(4x + y) 30 (7x + 2y)(3x + 4y) 24/ ...

\(a)=3x\cdot\left(2x-7-4x+5\right)=3x\cdot\left(-2x-2\right)=3x\cdot\left[-2\cdot\left(x+1\right)\right]\)

\(\frac{4x-1}{3x^2y}-\frac{7x-1}{3x^2y}\)

 \(=\frac{\left[\left(4x-1\right)-\left(7x-1\right)\right]}{3x^2y}\)

\(=\frac{\left(4x-1-7x+1\right)}{3x^2y}\)

\(=\frac{\left(-3x\right)}{3x^2y}\)

\(\frac{-1}{xy}\)

a, \(\left(3x-7\right)-\left(-5-7x\right)=4x+9\)

\(\Leftrightarrow3x-7+5+7x=4x+9\)

\(\Leftrightarrow3x+7x-4x=9+7-5\)

\(\Leftrightarrow\left(3+7-6\right)x=11\Rightarrow4x=11\Rightarrow x=\frac{11}{4}\notin Z\)

Vậy : \(x\in\varnothing\)

b, \(\left(3x-7\right)-\left(-5-7x\right)=5x+8\)

\(\Leftrightarrow3x-7+5+7x=5x+8\)

\(\Leftrightarrow3x+7x-5x=8+7-5\)

\(\Leftrightarrow\left(3+7-5\right)x=10\Rightarrow5x=10\Rightarrow x=10\div5=2\in Z\)

Vậy : x = 2

c, \(\left(3x-2\right)^3=125\Leftrightarrow\left(3x-2\right)^3=5^3\)

\(\Rightarrow3x-2=5\Rightarrow3x=5+2\Rightarrow3x=7\)

\(\Rightarrow x=7\div3\Rightarrow x=\frac{7}{3}\notin Z\)

Vậy \(x\in\varnothing\)

a, (3x-7)-(-5-7x)=4x+9

3x-7+5+7x=4x+9

3x+7x-4x=9+7-5

6x=11

x=11/6(thuộc Z t/m)

Vậy...

b, (3x-7)-(-5-7x)=5x+8

3x-7+5+7x=5x+8

3x+7x-5x=8+7-5

5x=10

x=2(thuộc Z t/m)

vây...

c, (3x-2)^3=125

(3x-2)^3=5^3

3x-2=5

x=7/3(thuộc Z thỏa mãn)

Vậy...

1)80-63x-7x-4x=10

80-[(63-7-4)x)]=10

80-52x=10

52x=80-10

52x=70

x=70/52

x=35/26

a) \(4x-3=11-3x\)

\(\Leftrightarrow4x+3x=11+3\)

\(\Leftrightarrow7x=14\)

\(\Leftrightarrow x=2\)

Vậy .............

b) \(x^3-4x^2+3x=0\)

\(\Leftrightarrow x\left(x^2-4x+3\right)=0\)

\(\Leftrightarrow x\left(x^2-x-3x+3\right)=0\)

\(\Leftrightarrow x\left[x\left(x-1\right)-3\left(x-1\right)\right]=0\)

\(\Leftrightarrow x\left(x-1\right)\left(x-3\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x-1=0\\x-3=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=0\\x=1\\x=3\end{matrix}\right.\)

Vậy .................

P/s: câu c bn gõ lại dc ko