Answer:
a = 40
Explanation:
-5a + 15/2a - 25 = 53.2 + 21.8: Add 25 to Isolate variable
-5a + 15/2a = 53.2 + 21.8 + 25: Combine Like Terms and create simmilar terms
-10/2a + 15/2a = 100: CLM again
5/2a = 100: multiply both sides by inverse of 5/2 to isolate variable
a = 40