Answer : C. The expression is not equivalent, but it is completely factored.
\(15c^2 + c - 28\) can be factored
15 * -28 = -420
21 and -20 are the factors whose sum is +1 and product is -420
\(15c^2 -20c + 21c - 28\)
\((15c^2 -20c) +(21c - 28)\)
\(5c(3c -4) + 7(3c - 4)\)
\((5c+7)(3c -4)\)
This is not equivalent to (c + 2)(15c - 14)
But (c + 2)(15c – 14) is completely factored
So , The expression is not equivalent, but it is completely factored.
