2/3 is equivalent to 4/6. Other fractions are 6/9, or 8/12.
A is just a variable to cover up any number you want. <span>a can be anything you want, such as the money in your bank account.
a+3
a=200
200+3</span>
I would assume that you convert 2.5 ounces into punds which would make it 0.15 lbs.