Perform the indicated operation and simplify.

Question

1. 1/4 + 1/3 = 2/3

2. 4/7 - 5/6 = 1/6

3. 3/5 * -4/7 = -12/35

4. 10/11 divided by 2/3 = 15/11

Answer 1

1/3 + 1/3 = 2/3
so how can 1/4 + 1/3 = 2/3 ?

6/6 - 5/6 = 1/6
so how can 4/7 - 5/6 = 1/6 ?

#3,4 are ok

Answer 2

1. 1/4 + 1/3
(1*3)/(4*3) + (1*4)/(3*4)
3/12 + 4/12
7/12 (not 2/3)