[tex]3r + 5 \\ + 7r + 3[/tex]

Answer: hope this helps!
3r+5+7r+3=10r+8
Step-by-step explanation:
3r+5+7r+3
Group like terms
=3r+7r+5+3
Add similar elements: 3r+7r=10r
Add the numbers:5+3=8
=10r+8