Question

If x varies as y and y= 7 when x = 18 find x when y = 21​

Answer 1

Step-by-step explanation:

If y=21,then x=31. Hope it helps you so much.so plz mark this answer as brainliest answer.

Answer 2

The value of x is 54 when y=21.

Step-by-step explanation:

Given : If x varies as y and y= 7 when x = 18.

To find : The value of x when y = 21​ ?

Solution :

When x varies as y means $y\propto x$

i.e. $y=kx$ .....(1)

where, k is the proportionality constant

Now, y= 7 when x = 18

Substitute in (1),

$7=k(18)$

$k=\frac{7}{18}$

The equation became $y=\frac{7}{18}x$

Now, put y=21

$21=\frac{7}{18}x$

$x=\frac{21\times 18}{7}$

$x=54$

Therefore, the value of x is 54 when y=21.

#Learn more

If x directly varies as y and x inversely varies as z then the relation between y and z is

https://brainly.in/question/5431296