Question

Suppose y varies directly with x.write a direct variation equation that relates x and y .y=7 1/2 when x=3

Answer 1

Answer:

$y=2.5x$

Step-by-step explanation:

We know that y varies directly with: $y$ ∝ $x$.

To convert this proportionality into an equality, we need a constant $k$.

$y$ = $kx$

We know that $y = 7.5$ when $x=3$ so we can write it as:

$y$ = $kx$

$7.5$ = $k(3)$

$k =2.5$

Now that we know the value of the constant $k$ is equal to  $2.5$ , we can write the this relation as:

$y=2.5x$

Answer 2

as y varies directly with x, the following equation can be established.

y = a * x

from the condition given by the question, we can know that

7.5 = a * 3

a = 7.5 / 3 = 2.5

thus, we can infer that the equation is

y = 2.5 * x