Answer:
-π
Explanation:
You want the horizontal shift required to get from y=sin(x) to y=3sin(x+π)-5.
Horizontal shift
The horizontal (right) shift in the graph is the opposite of the value that is added to x.
x +π ⇒ horizontal shift of -π (to the right)
The graph is shifted π units to the left.
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Additional comment
The attached graphs of the sine function (dashed red) and the given function (blue) are intended to highlight the shift for you. Corresponding parts of the graph are highlighted, and the amount of horizontal shift is indicated by the vertical green dotted lines.
You can see there is also vertical scaling (expansion) by a factor of 3, and a vertical downward shift by 5 units.