# If y varies directly with x, and if x = 7.5 when y = 10, how do you find x when y = 4?

**Solution:**

Given: y varies directly with x[direct variation]

y = ax where a is a constant of proportionality.

Now substitute the value of x and y

y = ax

10 = a(7.5)

a = 1.33

Determine the value of x by substituting the value of a and y

y = ax

4 = (1.33)x

So we get,

x = 3

Therefore, the value of x is 3.

## If y varies directly with x, and if x = 7.5 when y = 10, how do you find x when y = 4?

**Summary:**

If y varies directly with x, and if x = 7.5 when y = 10, x is 3 when y = 4.