The value of $9 x^{2} + 49 y^{2} - 42 x y$ when $x = 15$ and $y = 3$ is------------

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Solution

Consider the given expression.
$9 x^{2} + 49 y^{2} - 42 x y$

Put $x = 15$ and $y = 3$ , we get
$= 9 (15)^{2} + 49 (3)^{2} - 42 \times 15 \times 3$
$= 9 \times 225 + 49 \times 9 - 42 \times 15 \times 3$
$= 2025 + 441 - 1890$
$= 576$

Hence, this is the answer.

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Similar questions

9 x^{2} + 49 y^{2} - 42 x y

x = 15

y = 3

9 x^{2} - 42 x y + 49 y^{2}

3 x - 7 y = 8

36 x^{2} + 49 y^{2} + 84 x y

x = 3, y = 6

3 x - 7 y = 10

x y = - 1

9 x^{2} + 49 y^{2}

$I f 3 x - 7 y = 10 a n d x y = - 1, f i n d t h e v a l u e o f 9 x^{2} + 49 y^{2}$

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