Answer:
22x^2 -10xy + 12x
Step-by-step explanation:
To add and subtract polynomials, combine only like terms. When doing it vertically, stack polynomials and line up the same bases and exponents. Once this is done, simply add and subtract the coefficients. 
   10x^2 + 12xy + 4x
+ 12x^2 -22xy + 8x 
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22x^2 -10xy + 12x
Here we added 10 + 12 = 22, 12 + -22 = -10 and 4 + 8 = 12.
 
        
             
        
        
        
Yes it is already simplified because there is nothing else that you are able to do to it.
        
                    
             
        
        
        
Answer:
Step-by-step explanation:
Given that, 
ABC is an Isosceles triangle.
In an Isosceles triangle the opposite sides ( AB =AC) are equal; Their base angles ( < ABD = < ACD) are also equal to each other.
It is als given that D is the mid point of BC.
i.e., BD = CD
Therefore, 
By SAS theorem of congruency of triangles, 
ABD = ACD
If this is the answer required, hope it helps...