6m+23
You have to use distributive property, so 15x2=30 and 2x3m= 6m. You then subtract 30 from 7 and get 23. 
        
                    
             
        
        
        
Answer:
1 3/4 in
Step-by-step explanation:
 
        
             
        
        
        
Answer:
True 24=24
Step-by-step explanation:
4+8+12=3x8
12+12=24
24=24
 
        
             
        
        
        
Answer:
The 3rd option is correct. 
Step-by-step explanation:
This is because of an exponent rule that goes: 
(xy)^z = x^z(y^z) 
The whole thing gets raised to the power. Therefore only the 3rd one works (ps. if you can mark as brainliest that would be amazing, but if not that's fine)