Hey there!
In order to find the roots (aka zeroes) of a function, you will need to use some graphing software. Once you graph your given function, you will need to count how many times it intersects the x-axis and note where those intersections are. I attached a photo of what this function should look like graphed.
If you use software, you can pinpoint the exact locations of each root in cases like these where the lines don't intersect perfectly. Your roots look to be at about:
This will be your answer. Hope this helped you out! :-)