1. 4/7 + 10/7 - 9/7 = ?
2. 7/13 + 4/11 = ?
3. 2/5 - 5/8 = ?
4. 4 + 6 ²/3 - 2 ¹/2

help me please, i will mark you as the brainliest if you help me. ( advance thank you ) ​