Cards: -16,-35,18
We have to add the value of the cards and the value of the unknown card (x) , and that expression must be equal to zero.
(-16)+(-35)+18+x = 0
Solve for x:
-16-35+18+x =0
Combine like terms:
-33+x=0
Add 33 to both sides of the equation:
-33+x+33 =0+33
x=33
