In plain and short, what's 2/3 of 7/8? well, is just their product.
The vertex form:

(h,k) - the coordinates of the vertex

The coordinates of the vertex are
(-4,13).
2*10^6 + 6*10^5 + 3*10^3 +9*10^1 +4*10^0
see expanded form is adding the digits together. and it would be what ever one number is times 10 to the power of how many digits are after that number. you skip the 0's though. hope this helps
Hello from MrBillDoesMath!
Answer: +9
Discussion:
The opposite of a number is that number multiplied by -1. In our case the opposite number is (-1) * (- (abs(9))) = -1 * (-9) = +9
Thank you,
MrB