Toán Lớp 7: Solve each equation. Also, for each step, state the property of equality used.
1. ???? − 11 = 29
2. 16 = ???? + 20
3. 7 = 1 + ????
4. −9???? = 153
5. 2???? = −20
6. 12 = ???? − 1
7. ????/ 4= −13
8. −30 = −18 + ????
9. ???? + 15 = 32
10. −30 = ???? − 15
4. −9r = 153
5. 2m= −20
6. 12 = m − 1
7. x/ 4= −13
8. −30 = −18 + k
9. n+ 15 = 32
10. −30 = x − 15