Final answer:
An equivalent expression for -6 (1/5a - 1/6) is -6(6/30a - 1/6).
Step-by-step explanation:
An equivalent expression for -6 (1/5a - 1/6) is -6[(1/a)/5 - (1/6)].
To find an equivalent expression, we can multiply both the numerator and denominator of each fraction by a common multiple of the denominators.
In this case, the common multiple is 30. So, the equivalent expression is -6[(1/a * 6/6)/5 - (1/6 * 5/5)] = -6[(6/6a)/5 - (5/30)] = -6[(6/6a)/5 - (1/6)] = -6(6/30a - 1/6).