question_answer 1)

Simplify the expression and find its value when \[a=5\] and \[b=-3\] \[2({{a}^{2}}+ab+)+3-ab\].

Answer:

                \[2({{a}^{2}}+ab)+3-ab\]                 \[=2{{a}^{2}}+2ab+3-ab\]                             \[=2{{a}^{2}}+2ab-ab+3\]                             \[\left| \text{rearranging terms} \right.\]                 \[=2{{a}^{2}}+ab+3\]                 \[=2{{(5)}^{2}}+(5)(-3)+3=50-15+3\]                 \[=50+3-15=53-15=38\]