The answer should be;
-b^2 + 4b
-7b^3 / 7b-
-7 / 7 = -1
b^3 / b (^1) = b^2
Note that if there is no exponent after a variable, it's automatically a 1, also, when dividing exponents, you are basically subtracting...
Thus b^3 / b actually equals b^3 - b^1
Firstly, you need to multiply -1 by b^2 (since those two were originally together)
= -1b^2
Now you need to divide 28b^2 by 7b,
28 / 7 = 4 and b^2 / b = b
4 * b = 4b
So, your answer should be
-b^2 + 4b
