1/2+2/5. 1/2-2/53/4+2/3. 3/5-1/31/4-1/6. 3/5+1/3

Question

1/2+2/5. 1/2-2/5
3/4+2/3. 3/5-1/3
1/4-1/6. 3/5+1/3

Answer 1

1/2+2/5=5/10+4/10=9/10
3/4+2/3=9/12+8/12=17/12=1 12/5
1/4-1/6=3/12-2/12=1/12
1/2-2/5=5/10-4/10=1/10
3/5-1/3=9/15-5/15=4/15
3/5+1/3=9/15+5/15=14/15