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

\(\Leftrightarrow5x^2+14x-3=5\left(x^2-x-2\right)\)

\(\Leftrightarrow5x^2+14x-3=5x^2-5x-10\)

\(\Leftrightarrow19x+7=0\Leftrightarrow x=-\frac{7}{19}\)

a.\(x^2-y^2+x+y=\left(x+y\right)\left(x-y+1\right)\)

b.\(3\left(x^2-2xy+y^2\right)-12=3\left[\left(x-y\right)^2-4\right]=3\left(x-y+2\right)\left(x-y-2\right)\)

c.\(3\left(x+y\right)-\left(x^2+2xy+y^2\right)=\left(x+y\right)\left(3-x-y\right)\)

d.\(\left(x^3+3x^2y+3xy^2+y^3\right)-\left(x+y\right)=\left(x+y\right)^3-\left(x+y\right)=\left(x+y\right)\left[\left(x+y\right)^2-1\right]\)

\(=\left(x+y\right)\left(x+y-1\right)\left(x+y+1\right)\)

Số lớn hơn 100 là:

101;102;103;104;....

HT ~ K cho tớ nhaaa

#Army

100< 101,102,103,104,105,....

3x(x + 1) - (x - 2)(3x + 1) = 12

<=> 3x² + 3x - (3x² - 5x - 2) = 12 

<=> 3x² + 3x - 3x² + 5x + 2 = 12 

<=> 8x = 10 

<=> x = 1,25 

Vậy x = 1,25

3x(x+1)-(x-2)(3x+1)=12

x=5/4

Trả lời:

sửa: \(x^3-4x^2-8x+8\)

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

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

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

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