How many solutions does the following equation have |6×+12|=-18

This equation has no solution.

Reason: 
The absolute valued function, which is represented by straight bars, returns only positive values.
For example | - 5 | = 5
A negative result cannot be obtained from an absolute valued function. Since the given equation makes the absolute valued function equal to a negative value, which is not possible, so the equation has no solution or root.