The values of x and y vary directly and one pair of values are given. Write an equation that relates x and y. Simplify completely.

x=0.1, y=0.9
y=?x

y = m x

.9 = m (.1)
m = 9
y = 9 x

If the values of x and y vary directly, it means that they can be related through a proportion. The equation that relates x and y is given by:

y = kx

where k is the constant of variation.

To find the value of k, we can use the given pair of values x=0.1 and y=0.9:

0.9 = k(0.1)

To solve for k, divide both sides of the equation by 0.1:

0.9/0.1 = k

Simplifying this equation gives us:

k = 9

So the equation that relates x and y is:

y = 9x

Therefore, if you want to find y in terms of x, the relationship is y = 9x.

To write an equation that relates two variables, x and y, when they vary directly, we can use the equation:

y = kx

In this equation, k represents the constant of variation.

To find the specific equation for the given pair of values where x = 0.1 and y = 0.9, we can substitute those values into the equation and solve for k.

0.9 = k(0.1)

To solve for k, divide both sides of the equation by 0.1:

0.9 / 0.1 = k

The result is:

k = 9

Now that we have found the value of k, we can rewrite the equation with the specific constant of variation:

y = 9x

Therefore, the equation that relates x and y when they vary directly is:

y = 9x