Answer :

Answer:

a = 40

Step-by-step explanation:

(3a + 5)° and (2a - 25)° are a linear pair and sum to 180° , that is

3a + 5 + 2a - 25 = 180 ( simplify left side )

5a - 20 = 180 ( add 20 to both sides )

5a = 200 ( divide both sides by 5 )

a = 40