You mean -2x+5y=20 if it was that's how you do it
so if you're finding the x intercept the y will turn to 0 why because you're only looking for x their's no need for y
so it will be -2x+0=20
-2x=20 if it's multiplication then you change it to division
-2x/-2=20/-2
x=-10 
        
             
        
        
        
For circumference it’s 12x3.14= 37.68
        
                    
             
        
        
        
The large box is less expensive per ounce.  
  
               large box             small box
cost             4.16                    2.38
content        32oz                   14oz
cost/oz       0.13                      0.17
                 *4.16/32                *2.38/14
The large box is less expensive than the small box. The large box is cheaper by 0.04 per ounce.
        
                    
             
        
        
        
Since we want to know how far she goes every hour to multiply that by 4 to get how far she goes in 4 hours, we do 17/3.5 to get per hour miles = around 4.86. Multiply that by 4 to get around 19.43 miles