Question

Suppose that y varies directly with x

and y = 10 when x = 20. What is y
when x = 15?
It’s a fraction

Answer 1

15/2

Explanation:

y varies directly as x can be written as:

y & x

y = Kx

K = y/x

But from the question, we were told that:

y = 10

X = 20

K = y/x

K = 10/20

K = 1/2

The formula for the expression is:

y = Kx

y = 1/2 x

Now let us solve for y, when:

x = 15

y = 1/2 x

y = 1/2 x 15

y = 15/2