Answer:
number of periods per year m, times the number of periods n: simple interest amount = principal amount × (rate / m) × n.
Step-by-step explanation:
The equation: n - 4 = -15
Now let's solve our equation for n.
n - 4 = -15
Add 4 to both sides.
n = -11
You didn't write what to do with the fraction but I think you meant to ask to simplify it:
38b/-19
Multiply - 19 from top and bottom :
-2b