To solve the expression, first combine the fractions:
(1/5a + 1/7a) = (7/35a + 5/35a) = 12/35a
Then, multiply the combined fraction by a^2/4:
(12/35a) * (a^2/4) = 12a^2/140a = a/12
Therefore, the simplified expression is a/12.
To solve the expression, first combine the fractions:
(1/5a + 1/7a) = (7/35a + 5/35a) = 12/35a
Then, multiply the combined fraction by a^2/4:
(12/35a) * (a^2/4) = 12a^2/140a = a/12
Therefore, the simplified expression is a/12.