collect the like terms:
Solution: x^2-5xy+4y
P.S
get the photo math app. :)
Hope that helps. 
 
        
             
        
        
        
Multiply the coefficients and the powers of 10 with each other:

The numeric part simply yields

As for the powers of 10, you have to add the exponents, using the rule

So, we have

So, the final answer is

 
        
             
        
        
        
We know that 20 percent is 1/5

total price is $8,000
 
        
        
        
Take a look at all 3 expressions: numbers, terms, and exponents.
4, 8, and 6 all have a GCF of 2.
y^5, y^3, and y^2 have a GCF of y^2.
Therefore, the GCF is 2y^2. Removing it gets you:
2y^2(2y^3 + 4y - 3)
        
             
        
        
        
The answer is D. 2 x 8= 16