To determine how many books Tim read, we need to solve the equation [tex]\( r + 11 = 17 \)[/tex].
Let's break down the steps:
1. Our goal is to isolate the variable [tex]\( r \)[/tex] on one side of the equation. This will help us find out the exact number of books Tim read.
2. Currently, [tex]\( r \)[/tex] is on one side of the equation but it is being added to 11. To isolate [tex]\( r \)[/tex], we need to get rid of the 11 on the left side.
3. To eliminate the 11, we perform the inverse operation of addition, which is subtraction.
4. Specifically, we subtract 11 from both sides of the equation to maintain the equality.
The equation after subtracting 11 from both sides looks like this:
[tex]\[ r + 11 - 11 = 17 - 11 \][/tex]
Simplifying both sides, we get:
[tex]\[ r = 6 \][/tex]
Therefore, Tim read 6 books over the summer.
So, the correct answer is:
[tex]\[ \boxed{\text{b. Subtract 11 from both sides.}} \][/tex]
