Solve the following addition problems: 5+6, 7+4, 6+8, 8+4, 5+9, 6+7, 7+5, 9+6, 9+7, 8+8, 9+9, 8+9

Here are the solutions to the addition problems:

1)

$$5 + 6 = 11$$

The sum of 5 and 6 is 11.

$$\boxed{11}$$

2)

$$7 + 4 = 11$$

The sum of 7 and 4 is 11.

$$\boxed{11}$$

3)

$$6 + 8 = 14$$

The sum of 6 and 8 is 14.

$$\boxed{14}$$

4)

$$8 + 4 = 12$$

The sum of 8 and 4 is 12.

$$\boxed{12}$$

5)

$$5 + 9 = 14$$

The sum of 5 and 9 is 14.

$$\boxed{14}$$

6)

$$6 + 7 = 13$$

The sum of 6 and 7 is 13.

$$\boxed{13}$$

7)

$$7 + 5 = 12$$

The sum of 7 and 5 is 12.

$$\boxed{12}$$

8)

$$9 + 6 = 15$$

The sum of 9 and 6 is 15.

$$\boxed{15}$$

9)

$$9 + 7 = 16$$

The sum of 9 and 7 is 16.

$$\boxed{16}$$

10)

$$8 + 8 = 16$$

The sum of 8 and 8 is 16.

$$\boxed{16}$$

11)

$$9 + 9 = 18$$

The sum of 9 and 9 is 18.

$$\boxed{18}$$

12)

$$8 + 9 = 17$$

The sum of 8 and 9 is 17.

$$\boxed{17}$$