-10 because if you flip it 7-10=-3
        
             
        
        
        
Answer:
31 , 59
Step-by-step explanation:
a = b +28
a + b = 90 {Complementary}
b + 28 + b = 90    {Combine like terms}
2b + 28 = 90       {Subtract 28 form both sides}
        2b  = 90 - 28
        2b = 62      {Divide both sides by 2}
         b = 62/2
        b = 31
a = 31 + 28
a = 59
 
        
             
        
        
        
Answer: 
Step 4 : he should have divided both sides by negative seven 
Step-by-step explanation:
 
        
             
        
        
        
we have

Step 1
Applying the distributive property in the left side ( Multiply the factors on the left side)

therefore
<u>the answer is</u>

 
        
                    
             
        
        
        
Well if you have three and add negative 3 it equals 0