Answer:
Step-by-step explanation:
Your question has typographical errors. The equation is 2a + b = 15.7, not 2e+b-15.7
2a + b = 15.7
b = 15.7  - 2a
since a > b, a = 6.3 cm
b = 15.7 - 2·6.3 = 3.1 cm
 
        
             
        
        
        
x^2*(-3x)=-3x^3. The power of x becomes 3 because you add the powers of x. (2+1=3)
 
        
             
        
        
        
Answer:
The study is an observational study. 
Step-by-step explanation:
Observational study: In research methods, the term "observational study" is determined as one of the different studies that are being conducted by the researchers to observe or study the effects of a specific risk factor, treatment, diagnostic test, or some other intervention in the absence of an effort to change which participants are being exposed and which is not being exposed to it.
Types: Cohort study and case-control study.
In the question above, the given statement represents the observational study.
 
        
             
        
        
        
Answer:
D
Step-by-step explanation:
 15 + 2x + x + 3 = 3x + 18
hope this helps
 
        
                    
             
        
        
        
Answer:
0.706
Step-by-step explanation:
Convert 12/17 to decimal by dividing the numerator by denominator.
12 ÷ 17 = 0.70588.......
The nearest thousandth is the third decimal place.
If we round up: 0.706
If we round down: 0.705
Because the fourth digit is "8", we round up. 
If the digit after the one you want to round to is 5 or greater, then you round up. If the digit after is 4 or less, round down..
12 ÷ 17 = 0.70588....... ≈ 0.706