Answer :

AL2006
U + 4/5 = 2 and 1/3

Subtract 4/5 from each side of the equation:

U = (2 and 1/3) - (4/5)

Now it's just problem in plain old adding and subtracting fractions,
just like the ones you've done many times before.

First let's change (2 and 1/3) to a fraction:    2 and 1/3  =  7/3

So you have to find the value of  (7/3) - (4/5) .

In order to add or subtract fractions, they need to have a common denominator.
The least common multiple of 3 and 5 is 15, so that's a good choice.

7/3 = 35/15
4/5 = 12/15

Now the problem is:     (35/15) - (12/15).  

That's 23/15 . . . . . the same thing as 1 and 8/15 .  

That's the value of ' U '.  What an ugly number !
u + 4 / 5 = 2  1 / 3
u + 4 / 5 = [ ( 2 X 3 ) + 1] / 3
u + 4 / 5 = 7 / 3
u =( 7 / 3 ) - ( 4 / 5 )
   = ( 35 -12 ) / 15
   = 23 / 15 Answer