Question

Suppose that y varies directly with x. Given x=4 when y=20. Find y when x = 3

Answer 1

Answer:

y = 15

Step-by-step explanation:

Given: y varies directly with x, x=4 when y=20

To find:  y when x = 3

Solution:

As y varies directly as x, it means that as x increases, y also increases by the same factor.

As y varies directly with x,

$y=kx$

Here, k is a constant

As x = 4 when y = 20,

$20=4k\\k=\frac{20}{4}=5\\\Rightarrow y=5x$

Put x = 3

$y= 5(3) = 15$