Suppose y varies directly with x. Write an equation relating x and y.
y = −30 when x = 6
since y=kx, just find k:
-30 = k*6
k = -5
...
If y varies directly with x, we can write the relationship as:
y = kx
where k is the constant of variation.
To find the equation relating x and y, we need to find the value of k. We can substitute the given values into the equation:
-30 = k(6)
Now we can solve for k:
k = -30 / 6
k = -5
So the equation relating x and y is:
y = -5x
To write an equation relating x and y when y varies directly with x, we can use the formula for direct variation:
y = kx
Here, k represents the constant of variation. To find the value of k, we need to use the given information.
We are told that when x = 6, y = -30.
Substituting these values into the equation, we have:
-30 = k * 6
Now, we can solve for k by dividing both sides of the equation by 6:
k = -30 / 6
k = -5
Therefore, the equation relating x and y when y varies directly with x is:
y = -5x