The midpoint formula tells you that the a segment with endpoints (*a*, *b*) and (*c*, *d*) will have a midpoint at ((*a *+ *c*)/2,(*b *+ *d*)/2)

So we know that (*x *+ 9)/2 = 6 and (5 + *y*)/2 = 3. We can solve those!

(*x *+ 9)/2 = 6

*x *+ 9 = 12

*x* = 3

(5 + *y*)/2 = 3

5 + *y* = 6

*y* = 1

Therefore, *x* + *y* = 4.

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