Answer:
Inequality: [tex]3b+1+2\leq 18[/tex]
Toni can carry up to 5 books.
Step-by-step explanation:
"Up to" means you cannot exceed over the amount, meaning everything in her backpack has to be less than or equal to 18 lbs.
Add 1 and 2, to get 3 and subtract from both sides, which gets you [tex]3b\leq 15[/tex]
Finally, divide both sides by 3, which gets you 5.
