Answer:
Step-by-step explanation:
![(\frac{5}{2})^{x}+(\frac{5}{2})^{(x+3)}=(\frac{5}{2})^{x}+(\frac{5}{2})^{x}*(\frac{5}{2})^{3}\\\\=(\frac{5}{2})^{x}*[1+(\frac{5}{2})^{3}]](https://tex.z-dn.net/?f=%28%5Cfrac%7B5%7D%7B2%7D%29%5E%7Bx%7D%2B%28%5Cfrac%7B5%7D%7B2%7D%29%5E%7B%28x%2B3%29%7D%3D%28%5Cfrac%7B5%7D%7B2%7D%29%5E%7Bx%7D%2B%28%5Cfrac%7B5%7D%7B2%7D%29%5E%7Bx%7D%2A%28%5Cfrac%7B5%7D%7B2%7D%29%5E%7B3%7D%5C%5C%5C%5C%3D%28%5Cfrac%7B5%7D%7B2%7D%29%5E%7Bx%7D%2A%5B1%2B%28%5Cfrac%7B5%7D%7B2%7D%29%5E%7B3%7D%5D)
Therefore,

 
        
             
        
        
        
Answer:
x = 5
Step-by-step explanation:
18x-30-7x = 25
11x = 55
x = 55/11
x=5
 
        
                    
             
        
        
        
Answer:
Step-by-step explanation:
178.54-35.65=142.89
then you do 142.89/12.99=11
She bought 11 CDs
 
        
             
        
        
        
Answer:
GCF: 20
Step-by-step explanation:
The thing you want to do is factor both numbers down to their lowest primes.
40:2 * 2 * 2 * 5
60:2 * 2 * 5 * 3
Now underline what is in both sets of primes. I'll bold them. The number that is bolded comes from 2 * 2 * 5 which is 20
The highest common factor is 20