4a²=4b²-4a+1

=(2a)²-2*2a*1+1²-4b²= (2a-1)²-(2b)²(2a-1-2b)(2a-1+2b)

\(3b^2-10b+8\)

\(=3b^2-6b-4b+8\)

\(=3b^2-6b-\left(4b+8\right)\)

\(=3b\left(b-2\right)-4\left(b-2\right)\)

\(=\left(b-2\right)\left(3b-4\right)\)

phân tích đa thức thành nhân tử:

3b^2-10b+8

=3b^2-6b-4b+8

=3b(b-2)-4(b-2)

=(b-2)(3b-4)

3b^2-10b+8

= 3b^2-6b-4b+8

= 3b(b-2)-4(b-2)

= (3b-4)(b-2)

=5a(a²-2ab-2a+5b)

a) \(3xy^2-12xy+12x\)

\(=3x\left(y-4y+4\right)\)

b) \(3x^3y-6x^2y-3xy^3-6axy^2-3a^2xy+3xy\)

\(=3xy\left(x^2-2x-y^2-2ay-a^2+1\right)\)

\(=3xy\left[\left(x^2-2\cdot x\cdot1+1^2\right)-\left(y^2+2\cdot y\cdot a+a^2\right)\right]\)

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

\(=3xy\left(x-1-y-a\right)\left(x-1+y+a\right)\)

c) \(36-4a^2+20ab-25b^2\)

\(=6^2-\left[\left(2a\right)^2-2\cdot2a\cdot5b+\left(5b\right)^2\right]\)

\(=6^2-\left(2a-5b\right)^2\)

\(=\left(6-2a+5b\right)\left(6+2a-5b\right)\)

d) \(5a^3-10a^2b+5ab^2-10a+10b\)

\(=5a\left(a^2-2ab+b^2\right)-10\left(a-b\right)\)

\(=5a\left(a-b\right)^2-10\left(a-b\right)\)

\(=\left(a-b\right)\left[5a\left(a-b\right)-10\right]\)

\(=5\left(a-b\right)\left[a\left(a-b\right)-2\right]\)

\(=5\left(a-b\right)\left(a^2-ab-2\right)\)

a. 3xy²-12xy+12x

= 3x(y²-4y+4)

= 3x(y-2)²

b. 3x³y-6x²y-3xy³-6axy²-3a²xy+3xy

= 3xy( x²-2x-y²-2ay-a²+1)

= 3xy ((x²-2x+1)-(a²-2ay-y²))

=3xy((x-1)²-(a-y)²)

= 3xy((x-1+a-y)(x-1-(a-y))

=3xy(x-1+a-y)(x-1-a+y)

d. =( 5a(a²-2ab+b²))-(10(a+b))

= 5a(a-b)²-10(a-b)

=5a(a-b)(a-b)-10(a-b)

=(a-b)(5a(a-b)-10)

Hình như mik làm sai hết rồi

\(a,=\left(a-5\right)^2-4b^2=\left(a-2b-5\right)\left(a+2b-5\right)\\ b,=ax^2+a-a^2x-x=ax\left(a-x\right)+\left(a-x\right)=\left(ax+1\right)\left(a-x\right)\)

a: \(=\left(a-5-2b\right)\left(a-5+2b\right)\)

b: \(ax^2+a-a^2x-x\)

\(=ax\left(x-a\right)-\left(x-a\right)\)

\(=\left(x-a\right)\left(ax-1\right)\)

\(10a-25-a^2=-\left(a^2-10a+25\right)=-\left(a^2-2.a.5+5^2\right)=-\left(a-5\right)^2\)

`10a-25-a^2`

`=-(a^2-10a+25)`

`=-(a^2-2.a.5+5^2)`

`=-(a-5)^2`

Áp dụng hằng đẳng thức : `(a-b)^2=a^2-2ab+b^2`

-a ^2 + 10 a - 25

- ( a^2 -10 a + 25 )

- ( a - 5 )^2