The way you put it is confusing. I'll answer but the way you put it was confusing to me.
        
             
        
        
        
Answer:
3x+6.9 and 3x-4
Step-by-step explanation:
since 3 x x is 3x and the sign in the bracket is addition you place it there then place 3 x 2.3 
being 6.9.
1/3 x 9is 9/3 and 3 can multiply both sides to get 3/1 or 3 then bring the minus and 1/3 x 12 is 12/3 3 can multiply both sides to get 4/1 or 4
 
        
             
        
        
        
Answer:
86.4 km
Step-by-step explanation:
Since the cyclist travels 1.8km in a minute, he will travel 48 times that in 48 minutes:

 
        
             
        
        
        
Answer:
1/10
Step-by-step explanation:
P(a successful member
had Bertha as her trainer)  = P(Bertha being you trainer) x P(being successful if
                                                 trained by Bertha)
                                              = 1/3 x 30/100
                                              = 30/300
                                              = 1/10