If x and y vary directly and y is 18 when xx is 6, find y when x is 4.
If x and y vary directly, we can write the equation of direct variation as y = kx, where k is the constant of variation.
To find the value of k, we can use the given information that y is 18 when x is 6.
Using the equation y = kx and substituting x = 6 and y = 18, we have:
18 = k(6)
Dividing both sides by 6:
k = 18/6 = 3
Now, we can use the value of k to find y when x is 4.
Using the equation y = kx and substituting x = 4 and k = 3, we have:
y = 3(4) = 12
Therefore, when x is 4, y is equal to 12.