54
a rule I follow:
same signs positive,
different signs negative.
-9 * -3 = 27
27 + 27 = 54
Set up an equation 20=k(0.4)....to find k divide 20 by 0.4
Answer:
Solving the equation
for variable n we get 
Step-by-step explanation:
We need to solve the equation
for variable n
Solving:

Subtract both sides by 6p

Switch sides of equality

Divide both sides by 3

So, solving the equation
for variable n we get 
Any unknown number in an equation you represent with a variable