Find the product of $-3y (xy +y^2)$ and find its value for $x = 4$, and $y = 5$.

AcademicMathematicsNCERTClass 8

Given:

$-3y (xy +y^2)$

To do:

We have to find the product of $-3y (xy +y^2)$ and find its value for $x = 4$, and $y = 5$.

Solution:

$-3y (xy +y^2)=-3y \times xy - 3y \times y^2$

$= -3xy^2 -3y^{2+1}$

$= -3xy^2 - 3y^3$

If $x = 4, y = 5$, then

$-3xy^2 - 3y^3= -3 \times 4 \times (5)^2 - 3 \times (5)^3$

$= -12 \times 25 - 3 \times 125$

$= -300 - 375$

$= -675$

raja
Updated on 10-Oct-2022 13:19:29

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