Lizeth Herring

2022-12-30

If x varies directly as a square of y for y=6, x=72. Find x for y=9.

Belinda Solomon

Solution:
Since x varies directly as a square of y.
$\therefore x=k{y}^{2}$ , where k is any constant.
Substitute y=6, x=72 in above relation.
$⇒72=k·{6}^{2}⇒k=\frac{72}{36}\therefore k=2$
Therefore, the above expression becomes $x=2{y}^{2}$.
We have to find x for y=9.
$⇒x=2×{9}^{2}⇒x=2×81\therefore x=162$
Thus, the value of x is 162.

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