Answer:
Step-by-step explanation:
7 choose 2    or    
 =7! / (7-2)! 
=7*6*5*4*3*2*1  /  5*4*3*2*1
=7*6
=42
 
        
                    
             
        
        
        
1) x+17=20
 x-10=30
2) x/4=20
 x/30=2
3) 4(x+5)=40
4) x+3.2=6
5) A pizza place sells pizza for $5 per box. If I had $20 how many pizzas can I buy in all? (5x=20)
Hope this helps! Have a wonderful day.
        
             
        
        
        
$23.58 divided by 12 = $1.965
Each roll is about $1.97 (if you round up)
        
                    
             
        
        
        
Answer:
Solution : (15, - 11)
Step-by-step explanation:
We want to solve this problem using a matrix, so it would be wise to apply Gaussian elimination. Doing so we can start by writing out the matrix of the coefficients, and the solutions ( - 5 and - 2 ) --- ( 1 )

Now let's begin by canceling the leading coefficient in each row, reaching row echelon form, as we desire --- ( 2 )
Row Echelon Form :
 
Step # 1 : Swap the first and second matrix rows,

Step # 2 : Cancel leading coefficient in row 2 through  ,
,

Now we can continue canceling the leading coefficient in each row, and finally reach the following matrix.

As you can see our solution is x = 15, y = - 11 or (15, - 11).
 
        
             
        
        
        
100-15=85 
Therefore 0.85 is the multiplier
So 243.00 times by 0.85 = 206.55