Answer:
[tex]s=\frac{SA-\pi r^{2} }{\pi r }[/tex]
Step-by-step explanation:
To solve this expression for S we are going to proceed the following way:
[tex]SA=\pi rs+\pi r^{2} \\SA-\pi r^{2} =\pi rs\\\frac{SA-\pi r^{2} }{\pi r } =s[/tex]
Notice that first we had to took all the terms of the expression that didn't have s and we moved them to the right (with the opposite sign).
Once we had the term with s (πrs) on the left, we proceed to divide by πr to leave the s alone.
