Question

If x varies inversely with y and x = 4 when y = 9, how do you find x when y = 6?

Answer 1

Answer:

6

Step-by-step explanation:

Find the relation between y and x.

Let $y=\frac{a}{x}$, because x varies inversely with y.

Substitute $\left \{ {{x=4} \atop {y=9}} \right.$ into $y=\frac{a}{x}$.

$9=\frac{a}{4}$ ⇒ $a=36$

∴ Relation between y and x is : $y=\frac{36}{x}$

How to find x?

It is possible because we have already found that $y=\frac{36}{x}$.

Substitute $y=6$ into $y=\frac{36}{x}$.

$6=\frac{36}{x}$ ⇒ $x=6$