Factor this expression completely
-21x+28
First, we can factor out the greatest common factor of -7:
-21x + 28 = -7(3x - 4)
Next, we can see that the expression inside the parentheses can be factored:
3x - 4 = (3x - 4)
Therefore, the completely factored expression is:
-21x + 28 = -7(3x - 4)