addition and subtraction fractions

Addition w/like denominators

100

3/7 + 2/7 = 

5/7

200

3/5 + 2/5 = 

5/5 or 1

300

3/4 + 2/4 = 

5/4

subtraction w/like denominators

100

4/5 - 2/5

2/5

200

6/8 - 1/8 = 

5/8

300

11/12 - 6/12 = 

5/12

addition w/unlike denominators

100

1/2 + 1/4 = 

3/4

200

2/3 + 1/4 = 

11/12

300

4/9 + 2/6 = 

14/18

subtraction w/unlike denominators

100

6/10 - 1/5 = 

4/10

200

1/2 - 1/5 = 

3/10

300

5/8 - 2/5 =

9/40