Please help with the following problem:

Suppose that x and y vary directly, and x=4 when y=10. Write the function that models the direct variation.

y = kx

plug in the given values of x and y, then solve for k
rewrite the original equation, now that you know k

To write the function that models the direct variation, we need to find the constant of variation (k) first.

Direct variation can be represented by the formula: y = kx, where y represents the dependent variable, x represents the independent variable, and k represents the constant of variation.

Given that x and y vary directly, and x = 4 when y = 10, we can substitute these values into the formula:

10 = k * 4

To find the value of k, we divide both sides of the equation by 4:

10/4 = k

k = 2.5

Now that we have the value of k, we can write the function that models the direct variation:

y = 2.5x