) Problem 15: For the function below, y varies directly with x. Find the constant of variation (k). Then find the value of y when x = −0.3.
Note: y = kx (direct variation formula)
y = 4 when x = -3
First, let's find the constant of variation (k) using the given information:
y = kx
4 = k(-3)
4 = -3k
k = -4/3
Now that we have found k, we can use it to find the value of y when x = -0.3:
y = (-4/3)(-0.3)
y = 4/10
y = 0.4
Therefore, when x = -0.3, y = 0.4.