Add. Use models if needed.
PLZ HELP I WILL GIVE BRAINLIEST!!
PLZ EXPLAIN​

Step-by-step explanation:
1. 3x+5+4x-1
7x+4
2. 5x-3-2x+1
3x-2
3. -7x+4-5x-12
-12x-8
4. 4x-10-5x-2
-x-12
plz mark brainliest