Question

Q.13 Add the two expressions and then find the value: (4p² + 2pq - 3q² -1) and (3q² -4p² + 7pq -3) and then find the value, if p = -1 and q = 2 *​

Answer 1

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Q1) Add the two expression and then find the values :

$\pink{\frak{Given}} \begin{cases} (4p^2+2pq-3q^2-1).......(1) \\ (3q^2-4p^2+7pq-3)......(2) \\ To \: find \: the \: values =? \end{cases}$

$\: \bold{ \bf{ \large{ \underline{adding \: both \: expressions \: (1) \: and \: (2)}}}}$

$\: \\ \implies \sf{ \bold{ \: (4 {p}^{2} + 2pq - 3 {q}^{2} - 1) + (3 {q}^{2} - 4{p}^{2} + 7pq - 3)}}$

$\: \\ \implies \sf{ {4p}^{2} + 2pq - 3 {q}^{2} - 1 + 3 {q}^{2} - 4 {p}^{2} + 7pq - 3}$

$\: \\ \implies \sf{4 {p}^{2} - 4 {p}^{2} - 3 {q}^{2} + 3 {q}^{2} + 2pq + 7pq - 1 + ( - 3)}$

$\\ \implies \sf{ \cancel{4 {p}^{2} } - \cancel{4 {p}^{2} } - \cancel{3 {q}^{2} } + \cancel{3 {q}^{2} } + 7pq + 2pq - 1 - 3}$

$\: \implies \displaystyle \sf{9pq - 4}$

$\: \bullet\underline{ \bold{ \bf{now \: put \: the \: value \: of \: p = - 1 \: and \: q = 2}}}$

$\: \implies \sf{9( - 1)(2) - 4}$

$\: \implies \sf{ - 18 - 4}$

$\: \implies \sf{ - 22}$

$\: \red \bigstar \boxed{ \boxed{ \underline{ \bf{the \: answer \: will \: be \: - 22}}}}$

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❄ Hope this answer helps u

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