How would I solve this question? I need to solve for s.

4

Step-by-step explanation:

2r = 5s/2 - s/4                    ⇒ bring to common denominator2r = 10s/4 - s/42r = 9s/49s = 8r                                ⇒ multiply both sides by 4s = 8r/9                               ⇒ divide both sides by 9s = 8/9*9/2                         ⇒ replace r with 9/2, simplifys = 4                                    ⇒ answer

Ive seen this before! the answer is b