If the area of the triangle formed by the image of the first-order function y = KX + 3 and the two coordinate axes is 9, then the value of K is?

If the area of the triangle formed by the image of the first-order function y = KX + 3 and the two coordinate axes is 9, then the value of K is?

When x = 0, y = 3
When y = 0, x = - 3 / K
Then s = 1 / 2 * | x | * | y | = 1 / 2 * 3 * 3 / | K | = 9
|k|=1/2
K = 1 / 2 or K = - 1 / 2