3x³ + 6x²y+ 3xy²

=3x³ + 3x²y + 3x²y + 3xy²

= 3x²(x +y) + 3xy(x +y)

=(x+y)(3x² + 3xy)

= 3x(x+y)(x+y)

= 3x(x+y)²

x³ + y³ + 2x + 2y

= (x+y)(x² - xy + y²) + 2(x+y)

= (x+y)(x² - xy + y² +2)

a) (x-1)²

= x² - 2x.1 + 1²

=x² - 2x +1

b) (3-y)²

=3² - 2.3y + y²

= 9 -6y +y²

c)`(x-1/2)^2`

`= x<sup>2</sup>  - 2x. 1/2 + (1/2)^2`

`= x<sup>2</sup> - x + 1/4`

Sửa lại phần 2 nha

`(2x+1/2)^3= (2x)^3 + 3. (2x)^2 . 1/2 + 3.2x.(1/2)^2 + (1/2)^3 = 8x^3 + 6x^2 + 3/2 x + 1/8`

x² - y² + 4y Simplify ———————————— y² + ysqt⁴

STEP2:Pulling out terms

 2.1     Pull out factors :

   y² + ysqt⁴  =   y • (y + sqt⁴) 

Trying to factor a multi variable polynomial :

 2.2    Factoring    x² - y² + 4y 

Try to factor this multi-variable trinomial using trial and error 

 Factorization fails

Equation at the end of step2:

((((x³)-(3•(x²)))+2x)+1) x (x²-y²+4y) (((————————————————————————•d)•x)•((d•—)•y))+—————————— (((x²)-4x)+4) d y•(y+sqt⁴)

STEP3:

x Simplify — d

Equation at the end of step3:

((((x³)-(3•(x²)))+2x)+1) x (x²-y²+4y) (((————————————————————————•d)•x)•((d•—)•y))+—————————— (((x²)-4x)+4) d y•(y+sqt⁴)

STEP 4 :

Equation at the end of step4:

((((x³)-3x²)+2x)+1) (x²-y²+4y) (((———————————————————•d)•x)•xy)+—————————— (x²-4x+4) y•(y+sqt⁴)

STEP5:

x³ - 3x² + 2x + 1 Simplify ————————————————— x² - 4x + 4

Checking for a perfect cube :

 5.1    x³ - 3x² + 2x + 1  is not a perfect cube

Trying to factor by pulling out :

 5.2      Factoring:  x³ - 3x² + 2x + 1 

Thoughtfully split the expression at hand into groups, each group having two terms :

Group 1:  2x + 1 
Group 2:  x³ - 3x² 

Pull out from each group separately :

Group 1:   (2x + 1) • (1)
Group 2:   (x - 3) • (x²)

(3x-4)² - 9x(x+1) = 8x+5

<=> 9x² - 24x + 16 - 9x² -9x = 8x+5

<=> (9x²  - 9x²) - (24x + 9x) + 16=8x+5

<=> -33x + 16 = 8x +5

<=> -33x - 8x = 5-16

<=> -41x = -11

<=> x= 11/41

Vậy x = 11/41

-(x-4)(x+5)

=(4-x)(x+5)

=4(x+5) - x(x+5)

= 4x + 20 - x² -5x

= (4x-5x) + 20 -x²

= -x +20 - x²

-( x - 4 )(x + 5 )

( x + 4 )(x + 5 )

x^2 + 5x + 4x + 20

chắc vậy

\(=\left(3x-3\right)\left(5-x\right)=15x-3x^2-15+3x=18x-3x^{2-15}\)

\(=18-3x^2-15\)

đánh nhầm

đây 2k5 nè

2k9 không kết bạn được dồi =)

@Cỏ

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