How to solve 2/3y + 1/2=1/7?

You want to solve for "y" right?
First, subtract 1/2 in both sides.
This is what it will look like:
2/3y = 1/7 - 2/3
2/3y = -11/21

Second, multiply the reciprocal of 2/3 (which is 3/2).
The answer is -33/42.
Actually, it is (y = -33/42).

One way to solve it is to work directly with the fractions.
  2/3y + 1/2 = 1/7
  2/3y = 1/7 - 1/2 = 2/14 - 7/14 = -5/14    (subtract 1/2)
  y = (3/2)*(-5/14)    (multiply by 3/2)
  y = -15/28

Another way to solve it is to clear fractions first. The least common denominator of 2/3, 1/2, and 1/7 is 42. Multiplying the equation by 42, we get
  28y + 21 = 6
  28y = -15    (subtract 21)
  y = -15/28    (divide by 28)

I don't get how you get -11 ?
Or -33?