Ok so
-10, -6
4,-6
-3,-13
-3,1
should be it
What do you wanna know?
The annual interest rate is 2000•0,05=100
The new price you have to pay is 2000•1.05 (change factor)
The additive inverse of something is whats added to the original to get 0
So in this case n - n = 0, which is B :)
The answer is 2.34 x 10-11 g