Question

Разложите на множители:

1) 4x^2 - 20xy + 25y2 - 2x + 5y

2) 9x^2 - 42xy + 49y2 + 6x - 14y

3) x^2 - 9y^2 + 30yz - 25z^2

4) 81x^2 - 4y^2 + 24yz - 36z^2

Answer 1

1)...=(2x-5y)^2-(2x-5y)=( 2x-5y)(2x-5y-1)

2)...=(3x-7y)^2+2(3x-7y)=(3x-7y)(3x-7y+2)

3)...=x^2-(3y-5z)^2= (x-3y+5z)(x+3y-5z)

4)...=81x^2-(2y+6z)^2=(9x-2y-6z)(9x+2y+6z)