question_answer

lf\[A=4{{x}^{2}}+{{y}^{2}}-6xy,\,B=3{{y}^{2}}+12{{x}^{2}}+8xy\] and \[C=6{{x}^{2}}+8{{y}^{2}}+6xy,\]find A + B + C.

A) \[10{{x}^{2}}+9{{y}^{2}}+8xy\]  

B) \[20{{x}^{2}}+11{{y}^{2}}+14xy\]

C)        \[10{{y}^{2}}-9{{x}^{2}}-8xy\]    

D) \[22{{x}^{2}}+12{{y}^{2}}+8xy\]