Question

Phân tíc các đa thức sau thành nhân tử:

a, 3x²-6x

b,5x(x-3)-2(x-3)

c,x²-25+y²+2xy

d, 2x²+7x-15

Answer 1

a, \(3x^2-6x=3x\left(x-2\right)\)

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

c, \(x^2-25+y^2+2xy=\left(x+y\right)^2-25=\left(x+y-5\right)\left(x+y+5\right)\)

d, \(2x^2+7x-15=2x^2+10x-3x-15=2x\left(x+5\right)-3\left(x+5\right)=\left(2x-3\right)\left(x+5\right)\)

Answer 2

a.3x(x-3)

b.(x-3)(5x-2)

 

Answer 3

a) 3x(x-2)    

b) (x-3)(5x-2)

c) (x+y-5)(x+y+5)

d) (2x-3)(x+5)

 

Answer 4

c.(x+y-5)(x-y+5)

d.(x+5)(2x-3)

 

Answer 5

c, (x²+2xy+y²) - 25

= (x+y)² - 5²

= (x+y+5).(x+y-5)

Answer 6

a,   =3x(x-2)

b,   =(x-3)(5x-2)

c,   =(x^2+y^2+2xy)-25

     =(x+y)^2-25

     = (x+y-5)(x+y+5)

d,  đặt 2 ra ngoài sau đó thêm bớt để xuất hiện hằng đẳng thức 

Answer 7

a) 3x(x-2)

b) (x-3)(5x-2)

c) (x-y+5)(x-x-5)

d) (x+5)(2x-3)