31/3a–5

To simplify the expression 31/3a - 5, we need to simplify both terms separately.

To simplify 31/3a, we multiply the numerator (31) by the reciprocal of the denominator (3a): (31/3a) * (1/(3a)) = (31 * 1) / (3a * 3a) = 31 / (9a^2) = 31/(9a^2)

Now, we subtract 5 from this simplified fraction: 31/(9a^2) - 5 = 31/(9a^2) - 5 * (9a^2)/(9a^2) = 31/(9a^2) - (45a^2)/(9a^2) = (31 - 45a^2)/(9a^2)

Therefore, the simplified expression is (31 - 45a^2)/(9a^2).