Respuesta :

12+ 8 7/8+6+s=29 1/4

Convert 1/4= 2/8.

12+ 8 7/8+6+s= 29 2/8

Combine like terms.

26 7/8+s= 29 2/8

Subtract 26 7/8 on both sides. 

s= 2.375 or 2 3/8

The unknown side is equal to 2 3/8.

I hope this helps!
~kaikers