Answer:
1. x + 3 = 5, so x =2
2. x - 5 = 10, so x = 15
3. 4 - 3 = x, so x = 1
4. 9 - 0 = x, so x = 9
5. 18 + 3 = x, so x =21
6-10. Create and solve 5 equations of your own.
x+20=25, so x=5
30-x= 25, so x=5
3-x=1, so x=2
13+x=14, so x= 1
15-x=12, so x=3
19+2=x, so x=21