1. 8

2. 6

3. 5

4. 4

1. 1

2. a(1/3)

3. a³

4. a

1. (x+y)/xy

2. (x+y)/(m+n)

3. (mx+ny)/(m+n)

4. (mx+ny)/mn

1. 12

2. 48

3. 144

4. 36

1. (x²−y²)/xy

2. (2x²−y²)/xy

3. (y²−x²)/xy

4. (x²−2y²)/xy