Let's solve this step by step:

Calculate the first part of the expression: (7/10 - 2/5)
7/10 = 0.7 and 2/5 = 0.4
0.7 - 0.4 = 0.3

Now, calculate the second part of the expression: (1/4 + 5/6)
1/4 = 0.25 and 5/6 ≈ 0.83
0.25 + 0.83 = 1.08

Multiply the result of the first part by the result of the second part: 0.3 * 1.08 = 0.324

Now, divide the result by 6 1/2 (or 13/2):
0.324 ÷ 13/2 = 0.324 * 2/13 ≈ 0.0498

Therefore, the final result is approximately 0.0498.