Answer:
C. -7x^2 - 28
Step-by-step explanation:
Firstly simplify the bracket before doing anything;
4x(3x - 7) = 12x^2 - 28x
then go back to the question and substitute the expression(12x^2 - 28x) on the bracket and then work out the question;
12x^2 - 28x -19x^2...then group the values with the same exponent of x,
(12x^2 - 19x^2) - 28x
; -7x^2 - 28x