How to add two 2D histograms into a new 2D histogram

I have two 2D histograms which I want to add and store it in a new 2D histogram in the following way,
New2DHistogram = (100 x 2DHistogram1) + (50 x 2DHistogram2)
Is there any command in ROOT which can do this in a single line?

ROOT Version: 5.34/09
Platform: Scientific Linux

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