To solve this expression, we follow the order of operations which is parentheses, multiplication/division, and then addition/subtraction.

First, let's simplify the expression inside the parentheses:

(12/7 x 8/14 + 1/2) = (96/98 + 1/2) = (48/49 + 49/98) = (96/98)

Next, let's multiply the expression by 3/5:

(96/98) x (3/5) = (288/490) = 144/245

Therefore, the simplified expression is 144/245.