To solve for n, we need to isolate the variable on one side of the equation.
Starting with:
-4.2 = -2.1n
We can divide both sides by -2.1:
-4.2 / (-2.1) = n
n = 2
To check, we can substitute 2 back into the original equation:
-4.2 = -2.1(2)
-4.2 = -4.2
Since both sides are equal, our solution of n = 2 is correct.
Therefore, the answer is a. 2.