\(8x^3+60x^2y+150xy^2+125y^3=\left(2x\right)^3+3.\left(2x\right)^2.5y+3.2x.\left(5y\right)^2+\left(5y\right)^3\)

\(=\left(2x+5y\right)^3\)

a) = (3x)^2 + 2.3x.5+ 5^2 = (3x+5)^2

b) = (2/3x)^2-(4y)^2=(2/3x-4y)(2/3x+4y)

c) = -(9x^4-12/5x^2y^2+4/25y^4) = -[(3x^2)^2 - 2.3x^2.2/5y^2 + (2/5y^2)^2]= -(3x^2-2/5y^2)^2

d) = (x-5)^2 -  4^2= (x-5+4)(x-5-4) = (x-1)(x-9)

e) = (2x)^3 + 3.(2x)^2.(5y) + 3.(2x).(5y)^2 + (5y)^3 = (2x+5y)^3

f) = (8x)^2 - (8a+b)^2 = (8x-8a-b)(8x+8a+b)

g) = (7x-4-2x-1)(7x-4+2x+1) = (5x-5)(9x-3) = 5(x-1).3(x-3)=15(x-1)(x-3)

h) = (x-y)(x+y)- 2(x+y) = (x+y)(x-y-2)

# Chúc bạn học tốt #

Cảm ơn bạn!

mình khỏi ghi đề nha, bạ đọc tự hiểu nha

a) (3x+5)²

b) \(\frac{2}{3}\).\(\left(\frac{2}{3}x^4-24y^2\right)\)

d) x(x-10)+9

e) 4x²(2x + 15y) + 25y²(6x + 5y)  

f) b(-16a+b)

g) 15x(5x-4+1)

câu còn lại bạn tự làm nha, lười quá!

h) 

a

\(8x^3-\dfrac{1}{125}y^3\\ =\left(2x\right)^3-\left(\dfrac{1}{5}y\right)^3\\ =\left(2x-\dfrac{1}{5}y\right)\left[\left(2x\right)^2+2x.\dfrac{1}{5}y+\left(\dfrac{1}{5}y\right)^2\right]\\ =\left(2x-\dfrac{1}{5}y\right)\left(4x^2+\dfrac{2}{5}xy+\dfrac{1}{25}y^2\right)\)

b

\(-x^3+6x^2y-12xy^2+8y^3\\ =-\left(x^3-6x^2y+12xy^2-8y^3\right)\\ =-\left(x^3-3.2y.x^2+3.\left(2y\right)^2.x-\left(2y\right)^3\right)\\ =-\left(x-2y\right)^3\\ =-\left(x-2y\right)\left(x-2y\right)\left(x-2y\right)\)

a: 8x^3-1/125y^3

=(2x)^3-(1/5y)^3

=(2x-1/5y)(4x^2+2/5xy+1/25y^2)

b: =(2y-x)^3

a) \(8x^3-\dfrac{1}{125}y^3\)

\(=\left(2x\right)^3-\left(\dfrac{1}{5}y\right)^3\)

\(=\left(2x-\dfrac{1}{5}y\right)\left[\left(2x\right)^2+2x\cdot\dfrac{1}{5}y+\left(\dfrac{1}{5}y\right)^2\right]\)

\(=\left(2x-\dfrac{1}{5}y\right)\left(4x^2+\dfrac{2}{5}xy+\dfrac{1}{24}y^2\right)\)

b) \(-x^3+6x^2y-12xy^2+8y^3\)

\(=-\left(x^3-6x^2y+12xy^2-8y^2\right)\)

\(=-\left(x^3-3\cdot x^2\cdot2y+3\cdot x\cdot\left(2y\right)^2-\left(2y\right)^3\right)\)

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

a) Ta có : 64x² - (8x + y)² 

= (8x)² - (8x + y)² 

= (8x - 8x - y) (8x + 8x + y)

= -y(16x + y)

Bài 1:

a)\(64x^2-(8x+y)^2=-y\left(16x+y\right)\)

b)\((x+y+15)^2-2(x+y+15)+1\)

\(=\left(x+y+14\right)^2\)

c)\(8x^3+60x^2y+150xy^2+125y^3\)

\(=\left(2x+5y\right)^3\)

d)\(x^{16}-1\)

\(=\left(x-1\right)\left(x+1\right)\left(x^2+1\right)\left(x^4+1\right)\left(x^8+1\right)\)

Bài 2:

\(\left(n+7\right)^2-\left(n-5\right)^2\)

\(=\left(n+7+n+5\right)\left(n+7-\left(n+7\right)\right)\)

\(=24\left(n+1\right)\) chia hết 24

a: \(20m^3n^2-15m^4n^2+25m^5n^2\)

\(=5m^3n^2\left(4-3m+5m^2\right)\)

c: \(2x^4-32\)

\(=2\left(x^4-16\right)\)

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

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

(2x+5y)^3

đăng ít 1 thôi bn

a) 8x³ - 125=(2x)³-5³=(2x-5)(2x+5)

b) 1 - 27x³y⁶=1-3³x³(y²)³=1-(3xy²)³=(1-3xy²)(1-3xy²+9x²y⁴)

c)27x³ + y³/64=(3x)³ + y³/4³=(3x)³ + (y/4)³=(3x+y/4)(9x²-3xy/4+y²/16)

d) 27x³ + 125y³ = (3x)³+(5y)³=(3x+5y)(9x²-15xy+25y²)