question_answer

Add the following:

(a) \[7{{a}^{2}}bc,-3ab{{c}^{2}},3{{a}^{2}}bc,2ab{{c}^{2}}\]

(b) \[5{{x}^{2}}-3xy+4{{y}^{2}}-9,7{{y}^{2}}+5xy-2{{x}^{2}}+13\]

Answer:

(a) \[7{{a}^{2}}bc+-3ab{{c}^{2}}+3{{a}^{2}}bc+2ab{{c}^{2}}\]

\[\Rightarrow \,7{{a}^{2}}bc-3ab{{c}^{2}}+3{{a}^{2}}bc+2ab{{c}^{2}}\]

\[\Rightarrow \,10{{a}^{2}}bc-ab{{c}^{2}}\]

(b) \[\left[ 5{{x}^{2}}-3xy+4{{y}^{2}}-9 \right]+\left[ \text{ }7{{y}^{2}}+5xy-2{{x}^{2}}+13 \right]\]

\[\Rightarrow \,5{{x}^{2}}-3xy+4{{y}^{2}}-9+7{{y}^{2}}+5xy-2{{x}^{2}}+13\]

\[\Rightarrow \,3{{x}^{2}}+11{{y}^{2}}+2xy+4\]