Cardigans do Algebra

<laughing>If Anchorage receives x+2 feet of snow and dog owner y shovels 14z+12 cubic feet of snow away from the back fence, then how many d nonobaddogs hop over the previously 4′ fence to the neighbors yard. 
Solve for d. 
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Yes, that is correct. 2 nonobaddogs hop over the fence and tear trails around the neighbors (fortunately also fenced) back yard. 
Allie and Roscoe are oh so very pleased with themselves and their adventure. 
They were caked with snow. They came cheerfully when I called. I lifted them back over the fence. I thought I’d shoveled away enough snow. These two are even more athletic than I thought. 
Any bets on who led the adventure?