Answer: length of DE is about 3.3 ft
Step-by-step explanation:  A calculator is necessary!
DE is the unknown hypotenuse of the triangle 
get the sine of 23° = 0.3907311285
Use the equation for sine
<em>sin = o/h</em> . 
To find h,  Substitute values for sin and o.  O is EC, Opposite the 23° angle D
<em>0.3907311285 = 1.3/h</em> multiply both sides by h
h(0.3907311285) = 1.3 divide both sides by 0.3907311285
h = 1.3/0.3907311285
3.327096065 = h, the length of the hypotenuse, DE.
 
        
             
        
        
        
5x+3=3x+7
<em></em>-3     =   -3
2x+3=7
     -3= -3
2x=4
x=2 
        
                    
             
        
        
        
Answer:
The second and the third one
Step-by-step explanation: