8th grade = 3x = 3(47) = 141 band members.
7th + 8th = 188 
7th = x
8th = 3x
x + 3x = 188    ; x = 47 ;  47 + 3(47) = 47 + 141 = 188
4x = 188
4x / 4 = 188 / 4
x = 47 --> 7th grade
8th grade = 3x = 3(47) = 141
To check:
x + 3x = 188    ; x = 47 ; 
47 + 3(47) = 188
47 + 141 = 188
188 = 188
        
                    
             
        
        
        
20 didn't do it for this one.
        
             
        
        
        
Log(2x*12)=3
10^3=2x*12
1000=24x
1000/24=x
x=41.667
        
             
        
        
        
Answer:
i d k
Step-by-step explanation: