1/2 + 2/3=
give simplified answer

You need a common denominator of 6 because it's the least common denominator of 2 and 3. So you can change -1/2 to -3/6. And change 2/3 to 4/6. The new equation would be -3/6 + 4/6 = 1/6.

Cd is the perpendicular bisector of both xy and st, and cy=20.find xy