a: \(25x^2-\dfrac{10}{3}xy+\dfrac{1}{9}y^2=\left(5x-\dfrac{1}{3}y\right)^2\)

b: \(25x^2-15x+\dfrac{9}{4}=\left(5x-\dfrac{3}{2}\right)^2\)

c: \(\left(2x+\dfrac{1}{2}y\right)\left(4x^2-xy+\dfrac{1}{4}y^2\right)=8x^3+\dfrac{1}{8}y^3\)

d: \(\left(x^2-\dfrac{2}{3}\right)\left(x^4+\dfrac{2}{3}x^2+\dfrac{4}{9}\right)=x^6-\dfrac{8}{27}\)

a/ 4a²x² + 4abx + b²

b/ 16x² - 24xy + 9y²

* = 12xy

\(4x^2y^2+12xy+9=\left(2xy\right)^2+2.2xy.3+3^2=\left(2xy+3\right)^2\)

lộn toán lớp 8 ko phải toan lop 9

a)  \(x^2+20x+100=\left(x+10\right)^2\)

b)  \(y^2-14y+49=\left(y-7\right)^2\)

p/s: chúc bn học tốt

Bạn có thể giải cụ thể hơn hộ mk đc k ạ

x² + 20x + *

= x² + 2x .10 + 10²

= ( x + 10 )²

y² - * +49

= y² - 2y . 7 + 7²

= (y -7 )²

a) x²+20x+* =  \(x^2+2.x.10+10^2=\left(x+10\right)^2\)

b) \(y^2-2.y.7+7^2=y^2-14y+49=\left(y-7\right)^2\)

`a)x^2+20x+100=(x+10)^2`

`b)16x^2+24xy+9y^2=(4x+3y)^2`

`c)y^2-14y+49=(y-7)^2`

`d)9x^2-42xy+49y^2=(3x-7y)^2`

a, \(x^2+2x.10+100=\left(x+10\right)^2\)

\(b,16x^2+2.4x.3y+9y^2=\left(4x+3y\right)^2\)

\(c,y^2-14y+49=\left(y-7\right)^2\)

\(d,9x^2-2.3x.7x+49y^2=\left(3x-7y\right)^2\)

=(x-5y)²

= x²+20x +100

= y² -14y+47

..........

1/ \(x^2-10xy+25y^2=\left(x-5y\right)^2\)

2/ \(x^2+20x+100\)

3/ \(y^2-14y+49\)

4/ \(16x^2+24xy+9y^2\)

5/ \(9x^2-42xy+49y^2\)

6/ \(25x^2+90x+81\)

7/ \(64x^2-48x+9\)

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

\(x^2+8x+16=\left(x+4\right)^2\)

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

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