1. V = lwh
    V = (8)(4)(5)
    V = (32)(5)
    V = 160 units³
2. V = lwh + lwh
    V = (4)(2)(1) + (3)(1)(1)
    V = (8)(1) + (3)(1)
    V = 8 + 3
    V = 11 units³
3. V = leh + s³
    V = (9)(3)(4) + (3)³
    V = (27)(4) + 27
    V = 108 + 27
    V = 135 units³
4. V = lwh
    V = (3)(7)(2)
    V = (21)(2)
    V = 42 units³
        
             
        
        
        
Hello i am new here how are you doing
        
             
        
        
        
3/9 = 0.3333333336 ~ 0.333
        
             
        
        
        
Answer:
It is not valid since there is more than one variable being changed at one. 
Step-by-step explanation:
Jackson changed the brand of soil, but he also changes the amount of water, and the amount of sunlight the plants are receiving, so his conclusion that the soil was more effective is not valid.
 
        
             
        
        
        
The answer would be the first choice 4+b