Question

$p = 7x ^{2} + 5xy - {9y}^{2} \\ q = {4y}^{2} - {3x}^{2} - 6xy \\ r = { - 4x}^{2} + xy + {5y}^{2} \\ find \: the \: value \: of \: p + q +r$
please solve the above mentioned question​

Answer 1

Answer:

Answer will be zero,

All terms will cancel out each other

Answer 2

ANSWER :

• ★ If p = 7x² + 5xy - 9y² , q = 4y² - 3x² - 6xy and r = - 4x² + xy + 5y² ; then the value of p + q + r is equal to 0.

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SOLUTION :

❒ Given :-

• p = 7x² + 5xy - 9y²

• q = 4y² - 3x² - 6xy

• r = - 4x² + xy + 5y²

❒ To find :-

• Value of p + q + r = ?

❍ Putting the value of p, q and r we get,

• ★ p + q + r

= ( 7x² + 5xy - 9y² ) + ( 4y² - 3x² - 6xy ) + ( - 4x² + xy + 5y² )

= 7x² + 5xy - 9y² + 4y² - 3x² - 6xy - 4x² + xy + 5y²

= 7x² - 3x² - 4x² + 5xy - 6xy + xy - 9y² + 4y² + 5y²

= 7x² - 7x² - xy + xy - 9y² + 9y²

= 0

∴ p + q + r = 0

• Hence the value of p + q + r is equal to 0.