What is the factored form of the following expression?
x^2 - 10xy + 21y^2
(1 point)
(x - 3y)(x - 7y)
(x + 3y)(x - 7y)
(x + 3y)(x + 7y)
(x - 3y)(x + 7y)
x^2 - 10xy + 21y^2
(1 point)
(x - 3y)(x - 7y)
(x + 3y)(x - 7y)
(x + 3y)(x + 7y)
(x - 3y)(x + 7y)