Respuesta :

21x^2

you CAN'T factor 21x^2
bcalle
1 * 21 and 3 * 7 are the only factors of 21
You can match these up with the x^2 or have one x with each factor.
x * 21x
3x * 7x
x^2 * 21
1 * 21x^2
3 * 7x^2
3x^2 * 7