Question

we have f terms on both sides of the equation, and we want to get the f terms on one side. we can subtract \\(\frac{2}{3}f\\) on the left side of the equation so that there are no f terms on the left. then we need to subtract \\(\frac{2}{3}f\\) from the right to keep the equation balanced. go for it.
\\(\frac{2}{3}f + 5\\) \\(=\\) \\(f + 15\\)
\\(-\frac{2}{3}f\\) \\(\\ \\) \\(-\frac{2}{3}f\\)
\\(\square\\) \\(=\\) \\(\square\\)

Explanation:

Step1: Simplify left side

$\frac{2}{3}f + 5 - \frac{2}{3}f = 5$

Step2: Simplify right side

$f + 15 - \frac{2}{3}f = \frac{1}{3}f + 15$

Answer:

Left box: $5$
Right box: $\frac{1}{3}f + 15$