A rate is a ratio of two quantities: miles per hour, calories per cookie,dollars per person, ... a unit rate just specifies the units (miles, hours) of<span> the two quantities.</span>
Answer:
<h2>h = 18 cm</h2>
Step-by-step explanation:

Substitute:
<em>multiply both sides by 2</em>
<em>divide both sides by 13</em>

Multiply num and dem by 2 each to get 8/20