Question

Y varies directly with x, y is 27 when x is 9. what is x when y is 30

Answer 1

x = 10

Explanation:

Direct variation general equation:

The general equation for direct variation is given by:

y = kx, where

• y varies directly as/with x,
• and k is the constant of proportionality.

Finding k (the constant of proportionality):

Since y is 27 when x is 9, we can use substitute these values for the variables in the direct variation equation to find k, the constant of proportionality:

(27 = 9k) / 9

3 = k

Thus, the constant of proportionality is 9.

Finding x when y is 30:

Now we can find x when y is 30 by substituting in 3 for k and 30 for y in the direct variation equation:

(30 = 3x) / 3

10 = x

Thus, x is 10 when y is 30.