Answer:
I think its the third bubble. Hopefullly this helps. im pretty sure its correct.
Explanation:
1st. add rt to both sides so that it cancels out. That should give you xy= s+rt.
2nd. Then divide x from both sides to single out the y. since x is multiplying with y you must use the inverse operation and divide by X. This should leave you with y= (s+rt)÷x