Answer:
rise over run
Explanation:
rise refers to the number of units going u or down a graph
run refers to the number of units going left or right
it is seen as so;  ,
 ,  , or
 , or   
Don't panic when I included "delta". Delta, it refers/means the small mathematical triangle found beside the rise and run symbols of y and x
 
        
             
        
        
        
Mycorrhizae are associations between fungi and the roots of plants, where the Fungi provides minerals to the plant. It enabled plants and fungi to be the first organisms to invade land successfully 430 million years ago. In most cases the relationship between host plants and the mycorrhizal fungus is mutualistic, or mutually beneficial. The Mycorrhizal fungi come into direct contact with plant roots and with the soil, adding to the plants ability to gather nutrients and water from the soil through the fungus. 
        
             
        
        
        
Diverging plate boundaries, earthquakes occur as the plates pull away from each other. Volcanoes also form as magma rises upward from the underlying mantle along the gap between the two plates. We almost never see these volcanoes, because most of them are located on the sea floor.