If $6+10=16$6+10=16, what is the answer to $6+8$6+8?

If $7+10=17$7+10=17, what is the answer to $7+11$7+11?

If $10-5=5$10−5=5, what is the answer to $11-5$11−5?

If $10-7=3$10−7=3, what is the answer to $9-7$9−7?