Question

Dùng Hẳng Đẳng Thức, Phân Tích Đa Thức Thành Nhân Tử Chung

a) x\(^2\)-4y\(^2\)                d) x\(^2\)-10xy+25y\(^2\)

b) x\(^2\)-9y\(^2\)                e) 9x\(^2\)- 6x+1

c) (2x-1)\(^2\)- 4y\(^2\)        f) 25x\(^2\)+20x+4

 

Answer 1

a) \(=x^2-\left(2y\right)^2=\left(x-2y\right)\left(x+2y\right)\)

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

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

d) \(=x^2-10xy+\left(5y\right)^2=\left(x-5y\right)^2\)

e) \(=\left(3x\right)^2-6x+1=\left(3x-1\right)^2\)

f) \(=\left(5x\right)^2+20x+4=\left(5x+2\right)^2\)

Answer 2

\(a)x^2-4y^2=(x-2y)(x+2y)\\b)x^2-9y^2=(x-3y)(x+3y)\\c)(2x-1)^2-4y^2=(2x-1-2y)(2x-1+2y)\\d) x^2-10xy+25y^2=(x-5y)^2\\e)9x^2-6x+1=(3x-1)^2\\f)25x^2+20x+4=(5x+2)^2\)