Assume that y varies directly with x, then solve. If y=-18 when x=6,find x when y=6
y=kx
so, y/x = k, a constant.
You want x such that
6/x = -18/6
To solve this problem, we can use the direct variation equation, which states that y varies directly with x, and can be represented as y = kx, where k is the constant of variation.
To find the constant of variation (k), we can use the given values for y and x. We know that when y = -18 and x = 6, so we can substitute these values into the equation:
-18 = k * 6
Now we can solve for k:
k = -18 / 6
k = -3
Now that we have the constant of variation (k), we can substitute it back into the equation y = kx to find x when y = 6:
6 = -3x
To solve for x, we can divide both sides of the equation by -3:
(6 / -3) = x
-2 = x
Therefore, when y = 6, x = -2 is the solution.