Answer:
x = —6
Step-by-step explanation:
3 = x + 9
Collect like terms 
3 — 9 = x
— 6 = x
x = —6
 
        
             
        
        
        
Answer:
18 is 72% of 25 which is also known as 28% less of 25
Step-by-step explanation:
18/25=.72
1-.72=.28
.28=28%
 
        
                    
             
        
        
        
Any number raised to the power of 0 is 1.
Therefore, 15^0 = 1
        
             
        
        
        
100 = x + x/2
3x/2 = 100
x = 200/3
if there was 50% discount:
buying 1 would be $33.33
buying 2 would be $66.67