The given equation is
m = ak/n
We want to solve for k
The first step is to multiply both sides of the equation by n. We have
m * n = ak/n * n
mn = ak
The next step is to divide both sides of the equation by a. We have
mn/a = ak/a
mn/a = k
k = mn/a
The correct option is the second one
namely, let's rationalize the denominator in the fraction, for which case we'll be using the <u>conjugate</u> of that denominator, so we'll multiply top and bottom by its <u>conjugate</u>.
so the denominator is 5 + i, simply enough, its conjugate is just 5 - i, recall that same/same = 1, thus (5-i)/(5-i) = 1, and any expression multiplied by 1 is just itself, so we're not really changing the fraction per se.

-3x = -3 because you would multiply one of the equations by -1 to eliminate y.
The answer is 2 gallons of syrup per batch.