a) Thực hiện rút gọn VT = -2x – 64

Giải phương trình -2x – 64 = 0 thu được x = -32.

b) Thực hiện rút gọn VT = -62 x +12

Giải phương trình -62x + 12 = -50 thu được x = 1.

Mấy câu này khá giống nhau nhé anh (câu 1 giống câu 4 và 5, cấu 2 giống câu 3) =)))

Câu 1: 2x - 7 + (x - 14) = 0

<=> 3x -21 = 0

<=> 3x = 21 => x = 7

Câu 2:

x² - 6x = 0 <=> x.(x - 6) = 0 => \(\orbr{\begin{cases}x=0\\x-6=0\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=0\\x=6\end{cases}}\)

Chúc anh học tốt !!!

Câu 1, 2 có người làm rồi nên mik làm tiếp cho mấy câu tiếp. Cứ áp dụng A.B = 0 => A = 0 hoặc B = 0

3; ( x - 3 )( 16 - 4x ) = 0

=> x - 3 = 0 hoặc 16 - 4x = 0

=> x = 3 hoặc x = 4

Vậy x = 3 hoặc x = 4.

4; ( x - 3 ) - ( 16 - 4x ) = 0

=> x - 3 - 16 + 4x = 0

=> ( x + 4x ) - ( 3 + 16 ) = 0

=> 5x - 19 = 0

=> x = 19/5

Vậy x = 19/5

5; ( x + 3 ) + ( 16 - 4x ) = 0

=> x + 3 + 16 - 4x = 0

=> ( x - 4x ) + ( 16 + 3 ) = 0

=> 3x + 19 = 0

=> x = 19/3

Vậy x = 19/3

a) x² + 10x + 16 = 0

<=> x² + 2x + 8x + 16 = 0

<=> x( x + 2 ) + 8( x + 2 ) = 0

<=> ( x + 2 )( x + 8 ) = 0

<=> \(\orbr{\begin{cases}x+2=0\\x+8=0\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=-2\\x=-8\end{cases}}\)

b) 4x² - 12x - 7 = 0

<=> 4x² + 2x - 14x - 7 = 0

<=> 2x( 2x + 1 ) - 7( 2x + 1 ) = 0

<=> ( 2x + 1 )( 2x - 7 ) = 0

<=> \(\orbr{\begin{cases}2x+1=0\\2x-7=0\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=-\frac{1}{2}\\x=\frac{7}{2}\end{cases}}\)

a. \(x^2+10x+16=0\)

\(\Leftrightarrow x^2+8x+2x+16=0\)

\(\Leftrightarrow x\left(x+8\right)+2\left(x+8\right)=0\)

\(\Leftrightarrow\left(x+2\right)\left(x+8\right)=0\)

\(\Leftrightarrow\orbr{\begin{cases}x+2=0\\x+8=0\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=-2\\x=-8\end{cases}}\)

b. \(4x^2-12x-7=0\)

\(\Leftrightarrow4x^2+2x-14x-7=0\)

\(\Leftrightarrow2x\left(2x+1\right)-7\left(2x+1\right)=0\)

\(\Leftrightarrow\left(2x-7\right)\left(2x+1\right)=0\)

\(\Leftrightarrow\orbr{\begin{cases}2x-7=0\\2x+1=0\end{cases}\Leftrightarrow}\orbr{\begin{cases}2x=7\\2x=-1\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=\frac{7}{2}\\x=-\frac{1}{2}\end{cases}}\)

             Bài làm :

 \(\text{a) }x^2+10x+16=0\)

\(\Leftrightarrow x^2+8x+2x+16=0\)

\(\Leftrightarrow x\left(x+8\right)+2\left(x+8\right)=0\)

\(\Leftrightarrow\left(x+2\right)\left(x+8\right)=0\)

\(\Leftrightarrow\orbr{\begin{cases}x+2=0\\x+8=0\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=-2\\x=-8\end{cases}}\)

 \(\text{b) }4x^2-12x-7=0\)

\(\Leftrightarrow4x^2+2x-14x-7=0\)

\(\Leftrightarrow2x\left(2x+1\right)-7\left(2x+1\right)=0\)

\(\Leftrightarrow\left(2x-7\right)\left(2x+1\right)=0\)

\(\Leftrightarrow\orbr{\begin{cases}2x-7=0\\2x+1=0\end{cases}\Leftrightarrow}\orbr{\begin{cases}2x=7\\2x=-1\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=\frac{7}{2}\\x=-\frac{1}{2}\end{cases}.}\)

\(a,\Leftrightarrow\dfrac{3x^3+6x^2-3x-5x^2-10x+5}{x^2+2x-1}=10\\ \Leftrightarrow\dfrac{3x\left(x^2+2x-1\right)-5\left(x^2+2x-1\right)}{x^2+2x-1}=10\\ \Leftrightarrow3x-5=10\Leftrightarrow3x=15\Leftrightarrow x=5\\ b,\Leftrightarrow\left(x^4+2x^2-4x^2-8\right):\left(x-2\right)=0\\ \Leftrightarrow\left[\left(x^2-4\right)\left(x^2+2\right)\right]:\left(x-2\right)=0\\ \Leftrightarrow\left[\left(x-2\right)\left(x+2\right)\left(x^2+2\right)\right]:\left(x-2\right)=0\\ \Leftrightarrow\left(x+2\right)\left(x^2+2\right)=0\Leftrightarrow x=-2\left(x^2+2>0\right)\\ c,\Leftrightarrow\dfrac{x\left(x-4\right)}{\left(x-4\right)^2}=0\Leftrightarrow\dfrac{x}{x-4}=0\Leftrightarrow x=0\)

b: \(\Leftrightarrow x^4-4x^2+2x^2-8=0\)

hay x=-2

Trả lời:

a, ( x² - 4x + 16 )( x + 4 ) - x ( x + 1 )( x + 2 ) + 3x² = 0

<=> x³ + 4x² - 4x² - 16x + 16x + 64 - x ( x² + 3x + 2 ) + 3x² = 0 

<=> x³ + 64 - x³ - 3x² - 2x + 3x² = 0

<=> 64 - 2x = 0

<=> 2x = 64

<=> x = 32

Vậy x = 32 là nghiệm của pt.

b, ( 8x + 2 )( 1 - 3x ) + ( 6x - 1 )( 4x - 10 ) = - 50

<=> 8x - 24x² + 2 - 6x + 24x² - 60x - 4x + 10 = - 50

<=> - 62x + 12 = - 50

<=> - 62x = - 62

<=> x = 1

Vậy x = 1 là nghiệm của pt.

a) x^3 - 64 - x^3 +6x = 2

(x^3 - x^3) + 6x = 2+64 quy tắc chuyển vế nhé bạn

6x = 66

x = 66:11

x = 6

a) (x - 1)³ - x(x - 2)² - (x - 2) = 0

<=> x³ - 2x² + x - x² + 2x - 1 - x³ + 4x² - 4x - x + 2 = 0

<=> x² - 2x + 1 = 0

<=> x² - 2.x.1 + 1² = 0

<=> (x - 1)² = 0

        x - 1 = 0

        x = 0 + 1

        x = 1

=> x = 1

a)Ta có : \(\left(x-1\right)^3-x\left(x-2\right)^2-\left(x-2\right)=0\)

\(=>\left(x-1\right)^3-\left(x^2-2x\right)\left(x-2\right)-\left(x-2\right)=0\)

\(=>\left(x-1\right)^3-\left(x-2\right)\left(x^2-2x+1\right)=0\)

\(=>\left(x-1\right)^3-\left(x-2\right)\left(x-1\right)^2=0\)

\(=>\left(x-1\right)^2\left(x-1-x+2\right)=0\)

\(=>\left(x-1\right)^2=0=>x-1=0=>x=1\)

Vậy x=1

b)(2x+5)(2x-7)-(4x+3)²=16

\(=>4x^2-4x-35-16x^2-24x-9-16=0\)

\(=>-\left(12x^2+28x+60\right)=0\)

\(=>12\left(x^2+\frac{7}{3}x+\frac{5}{3}\right)=0\)

\(=>x^2+\frac{7}{3}x+\frac{49}{36}+\frac{11}{36}=0=>\left(x+\frac{7}{6}\right)^2+\frac{11}{36}=0\)

Lại có \(\left(x+\frac{7}{6}\right)^2\ge0=>\left(x+\frac{7}{6}\right)^2+\frac{11}{36}\ge\frac{11}{36}>0\)

Vậy ko có giá trị nào của x thỏa mãn đề bài

\(=>x^2+\frac{7}{3}x+\frac{49}{36}+\frac{11}{36}=0=>\left(x+\frac{7}{6}\right)^2+\frac{11}{36}=0\)

a) \(x^2-2x=0\)

\(x\left(x-2\right)=0\)

\(\Rightarrow\orbr{\begin{cases}x=0\\x-2=0\end{cases}\Rightarrow\orbr{\begin{cases}x=0\\x=2\end{cases}}}\)

b) \(\left(3x-1\right)^2-16=0\)

\(\left(3x-1\right)^2-4^2=0\)

\(\left(3x-1-4\right)\left(3x-1+4\right)=0\)

\(\left(3x-5\right)\left(3x+3\right)=0\)

\(\Rightarrow\orbr{\begin{cases}3x-5=0\\3x+3=0\end{cases}\Rightarrow\orbr{\begin{cases}x=\frac{5}{3}\\x=-1\end{cases}}}\)

c) \(x^2-25x=0\)

\(x\left(x-25\right)=0\)

\(\Rightarrow\orbr{\begin{cases}x=0\\x-25=0\end{cases}\Rightarrow\orbr{\begin{cases}x=0\\x=25\end{cases}}}\)

d) \(\left(4x-1\right)^2-9=0\)

\(\left(4x-1\right)^2-3^2=0\)

\(\left(4x-1-3\right)\left(4x-1+3\right)=0\)

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

\(\Rightarrow\orbr{\begin{cases}4x-4=0\\4x+2=0\end{cases}\Rightarrow\orbr{\begin{cases}x=1\\x=\frac{-1}{2}\end{cases}}}\)

a) \(x^2-2x=0\)

\(x.\left(x-2\right)=0\)

\(\Rightarrow\orbr{\begin{cases}x=0\\x-2=0\end{cases}\Rightarrow\orbr{\begin{cases}x=0\\x=2\end{cases}}}\)

vậy..

b) \(\left(3x-1\right)^2-16=0\)

\(\left(3x-1\right)^2=16\)

\(\left(3x-1\right)^2=4^2=\left(-4\right)^2\)

\(\Rightarrow\orbr{\begin{cases}3x-1=4\\3x-1=-4\end{cases}\Rightarrow\orbr{\begin{cases}x=\frac{5}{3}\\x=-1\end{cases}}}\)

vậy ...

c) \(x^2-25x=0\)

\(x.\left(x-25\right)=0\)

\(\Rightarrow\orbr{\begin{cases}x=0\\x-25=0\end{cases}\Rightarrow\orbr{\begin{cases}x=0\\x=25\end{cases}}}\)

vậy ....

d) \(\left(4x-1\right)^2-9=0\)

\(\left(4x-1\right)^2=3^2=\left(-3\right)^2\)

\(\Rightarrow\orbr{\begin{cases}4x-1=3\\4x-1=-3\end{cases}\Rightarrow\orbr{\begin{cases}x=1\\x=\frac{1}{2}\end{cases}}}\)

vậy ...

a)\(x^2-2x=0\)

\(\Rightarrow x\left(x-2\right)=0\)

\(\Rightarrow\hept{\begin{cases}x=0\\x-2=0\end{cases}}\Rightarrow\hept{\begin{cases}x=0\\x=2\end{cases}}\)

b)\(\left(3x-1\right)^2-16=0\)

\(\left(3x-1-4\right)\left(3x-1+4\right)=0\)

\(\Rightarrow\hept{\begin{cases}3x-1-4=0\\3x-1+4=0\end{cases}}\Rightarrow\hept{\begin{cases}x=\frac{5}{3}\\x=-1\end{cases}}\)

c)\(x^2-25x=0\)

\(x\left(x-25\right)=0\)

\(\Rightarrow\hept{\begin{cases}x=0\\x-25=0\end{cases}\Rightarrow}\hept{\begin{cases}x=0\\x=25\end{cases}}\)

d)\(\left(4x-1\right)^2-9=0\)

\(\left(4x-1-3\right)\left(4x-1+3\right)=0\)

\(\Rightarrow\hept{\begin{cases}4x-1-3=0\\4x-1+3=0\end{cases}\Rightarrow\hept{\begin{cases}x=1\\x=-\frac{1}{2}\end{cases}}}\)

a)\(x\left(x^2-0,25\right)=0\)

TH1:\(x=0\)        TH2:\(x^2-0,25=0\)

                                      \(x^2=0,25=>x=0,5\)

Vậy x E \(\hept{0,5;0}\)