3a- 10° 3b- 55°
4a- 135° 4b- 45°
Complementary angles add up to 90°
Supplementary angles add up to 180°
        
             
        
        
        
My "work" is to enter the equations into a graphing calculator and let it show me the answers--just as your "work" is to copy the question to Brainly.
The solutions are
  (x, y) = (-0.5, 7.5)
  (x, y) = (3, 25)
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When you equate the expressions for y, you get the quadratic
  2x² -5x -3 = 0
  (2x +1)(x -3) = 0
  x = -1/2 or 3
  y = 5(x +2) = 15/2 or 25
 
        
        
        
i could tell you what n is if you tell me what t is
sorry not much help 
 
        
                    
             
        
        
        
Answer:
Y = 60 degrees and X = 12 
Step-by-step explanation:
x+3 and 15 are congruent so x+3 = 15, 12+3 = 15 therefore x = 12
y = 60 vertically opposite angles are equal. :D
 
        
                    
             
        
        
        
Answer:
B
Step-by-step explanation:
x² - 4x - 7 = 0
(x - 2)² = 11