Answer:
r = -1
Step-by-step explanation:
Multiply both sides by the common denominator (14)
[tex]14(\frac{1}{2} + \frac{r}{7}) = \frac{5}{14} (14)[/tex]
Distribute
[tex]7 + 2r = 5[/tex]
Subtract both sides by 7
[tex]2r = -2[/tex]
Divide both sides by 2
[tex]r = -1\\[/tex]
