[tex]\huge{\boxed{r=34}}[/tex]
First, let's write this as an equation. The sum (addition) of [tex]\bf{r}[/tex] and [tex]\bf{45}[/tex] is [equal to] [tex]\bf{79}[/tex].
[tex]r+45=79[/tex]
Now, we need to get the variable by itself on one side of the equals sign. We can do this by subtracting [tex]45[/tex] from each side.
[tex]\boxed{r=34}[/tex]
