Divide -3
-3/-3a = 15/-3
a = -5
        
                    
             
        
        
        


<h3><em>refer</em><em> to</em><em> the</em><em> attachment</em></h3><h2><u>hope</u><u> it</u><u> helps</u></h2><h2 />
 
        
             
        
        
        
Answer:
x = 7
Step-by-step explanation:
QY = 5x
YZ = 18
QZ = 53
Thus:
QY + YZ = QZ (segment addition postulate)
5x + 18 = 53
5x = 53 - 18 (subtraction property of equality)
5x = 35
Divide both sides by 5
x = 7