10y + 20 is an equivalent expression
        
                    
             
        
        
        
(x - 2)^2 will always be positive and will have a minimum value of  0 
so f(x) will have minimum of 2
Range is [2,∞)
        
             
        
        
        
Answer:
   8
Step-by-step explanation:
The fact that DE is perpendicular to AC means triangles AED and CED are congruent and side AD is equal in length to side CD.
   5x -20 = 2x +4
   3x = 24 . . . . . . . add 20-2x
   x = 8 . . . . . . . . . .divide by 3
The value of x is 8.
 
        
             
        
        
        
This can be solved using a system of equations. 

Subtract y from both sides.

Substitute:

Subtract 80 from both sides:

Divide both sides by 5:

Substitute.
