find the GCF and then the factor

To find the greatest common factor (GCF) of -63y^2 + 28y, we can factor out the greatest common factor of the coefficients, which is 7, and the greatest common factor of the variables, which is y. The GCF is 7y.

Now, we can factor out 7y from each term:

-63y^2 + 28y = 7y(-9y + 4)

Therefore, the GCF is 7y and the factored form is 7y(-9y + 4).