Remember you have to write complete questions in order to get exact and good answers. Here I can only help you in a general way since you didn't provide any function.
The x-intercept of any function occurs when we set . Suppose you have a function expressed as follows:
In order to find the x-intercept (or x-intercepts) we set:
So we will have an equation in terms of the variable x. When solving this equation we get the x-intercept. An x-intercept located to the left of the origin implies that we will have a negative number. For instance:
Those x-intercepts are located to the left of the origin.