Answer:
(TZ - 2P)/2 = S
Explanation:
Multiply both sides by Z
T*Z = Z*2(S + P)/Z
TZ = 2*(S + P) Divide by 2
TZ/2 = 2(S + P)/2 Do the division
TZ/2 = S + P Subtract P from both sides
TZ/2 - P = S That's one answer. You could refine it.
Multiply P by 2 so that you can put TZ - 2P over a common denominator.
(TZ - 2P)/2 = S Is another answer.
I think the second one is probably the best one.