\(6x^2-19x+15=6x^2-9x-10x+15\)

\(=3x\left(2x-3\right)-5\left(2x-3\right)\)

\(=\left(3x-5\right)\left(2x-3\right)\)

a) xy+3x-7y-21

=x(y+3)-7(x+3)

=(x-7)(y+3)

b)2xy-15-6x-5y

=2x(y-3)-5(-3+y)

=(2x-5)(y-3)

c)2x^2y+2xy^2-2x-2y

=2x(xy-1)+2y(xy-1)

=(2x+2y)(xy-1)

x(x+3)-5x(x-5)-5(x+3)

=(x-5)(x+3)-5x(x-5)

=(x-5)(x+3-5x)

Câu cuối mình bị nhầm dòng cuối phải là (x-5)(x+3+x-5)=(x-5)(2x-2)nha bạn

a) xy+3x-7y-21=(xy+3x)-(7y+21)= x(y+3)-7(y+3)=(y+3)(x-7)

b)2xy-15-6x+5y=(2xy-6x)+(5y-15)=2x(y-3)+5(y-3)=(y-3)(2x+5)

c)2x^2y+2xy^2-2x-2y=2xy(x+y)-2(x+y)=2(x+y)(xy-1)

d) x(x+3)-5x(x-5)-5(x+3)=[x(x+3)-5(x+3)]-5x(x-5)=(x+3)(x-5)-5x(x-5)=(x-5)(x+3-5x)=(x-5)(3-4x)

ko ra được đâu

Ta có:  \(\Delta\)= b^2 - 4ac

                    = (-6)^2  -  4.1.15 

                    =-24

     Vì\(\Delta\)< 0  nên phương trình vô nghiệm => không thể phân tích

1A:

a: \(x^3+2x=x\left(x^2+2\right)\)

b: \(3x-6y=3\left(x-2y\right)\)

c: \(5\left(x+3y\right)-15x\left(x+3y\right)\)

\(=5\left(x+3y\right)\left(1-3x\right)\)

d: \(3\left(x-y\right)-5x\left(y-x\right)\)

\(=3\left(x-y\right)+5x\left(x-y\right)\)

\(=\left(x-y\right)\left(5x+3\right)\)

1A. a. x(x²+2) 

b. 3(x-2y)

c. 5(x+3y)(1-3x) 

d. (x-y) (3-5x)

1B. a. 2x(2x-3)

b.xy(x²-2xy+5)

c. 2x(x+1)(x+2)

d. 2x(y-1)+2y(y-1)=2(y-1)(x-y)

1B:

a: \(4x^2-6x=2x\left(2x-3\right)\)

b: \(x^3y-2x^2y^2+5xy\)

\(=xy\left(x^2-2xy+5\right)\)

         \(6x^2+13x-15\)

\(=6x^2+18x-5x-15\)

\(=6x.\left(x+3\right)-5.\left(x+3\right)\)

\(=\left(x+3\right).\left(6x-5\right)\)

\(6x^2+13x-15\)

\(=6x^2+18x-5x-15\)

\(=6x\left(x+3\right)-5\left(x+3\right)\)

\(=\left(x+3\right)\left(6x-5\right)\)

\(6x^2+13x-15\)

\(\Rightarrow6x^2+18x-5x-15x\)

\(\Rightarrow6x\times\left(x+3\right)-5\times\left(x+3\right)\)

\(\Rightarrow\left(x+3\right)\times\left(6x-5\right)\)

Code : Breacker

Ta có:  x 2 + 6 x + 9 = x 2 + 2 . x . 3 + 3 2 = ( x + 3 ) 2 .

Ta có:  x 2 + 6 x + 9 = x 2 + 2 . x . 3 + 3 2 = ( x + 3 ) 2 .

Ta có :  4 x 2 - 6 x = 2 x . 2 x - 3 . 2 x = 2 x ( 2 x - 3 ) .