Bài 1: 

c: \(\left(-5x-y\right)^3=-125x^3-75x^2y-15xy^2-y^3\)

h: \(\left(3y-2x^2\right)^3=27y^3-54y^2x^2+36yx^4-8x^6\)

Bài 1:

c. (-5x - y)³ = -125x³ - 50x²y - 10xy² - y³

d. (3y - 2x²)³ = 27y³ - 18x²y² + 24xy⁴ - 8x⁶

\(x^2+x+\dfrac{1}{4}=\left(x+\dfrac{1}{4}\right)^2\)

\(8x^3+27=\left(2x+3\right)\left(4x^2-6x+9\right)\)

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

\(a,=\left(2a-1\right)\left(2a+1\right)\\ b,=\left(x-\sqrt{3}\right)\left(x+\sqrt{3}\right)\\ c,=\left(16-3x\right)\left(16+3x\right)\\ d,Sửa:-36x^2+24x-4=-4\left(9x^2-6x+1\right)=-4\left(3x-1\right)^2\)

\(a,=\left(2a-1\right)\left(2a+1\right)\\ b,=\left(x-\sqrt{3}\right)\left(x+\sqrt{3}\right)\\ c,=\left(16-3y\right)\left(16+3y\right)\)

a) = 1003 2 - 2.3.1003 + 3²

= (1003 - 3)² = 1000² = 1000000

b) = 998² + 4. (998 + 1)

= 998² + 2.2.998 + 2²

= (998 + 2)² = 1000² = 1000000

a) = 1003² - 2.3.1003 + 3²

= (1003 - 3)² = 1000² = 1000000

b) = 998² + 4. (998 + 1)

= 998² + 2.2.998 + 2²

= (998 + 2)² = 1000² = 1000000

cám ơn các bạn

\(9-x^2-6x=-\left(9+x^2+6x\right)=-\left(x^2+2.3x+3^2\right)=-\left(x+3\right)^2\)

e tưa học lp8   :)

bài mình tại sao lại sai 

- (5 + 4y) (5 - 4y) = - [5² - (4y)²] = - (25 - 16y²) = - 25 + 16y² = 16y² - 25 

-(5+4y)(5-4y)  =  - ( 5² - 16 y²) = -( 25 - 16y²)

=(3x + 1)(3x - 1).2 = (9x² - 1).2 = 18x² - 2

\(\left(1+3x\right)\left(3x-1\right).2\)

\(=\left[\left(3x\right)^2-1^2\right].2\)

   \(=\left(9x^2-1\right).2\)

\(=18x^2-2\)

a)1002001

b)899,99

Nếu thấy đúng cho mình 1 k nha !

Học giỏi