Answer: w lesser than or equal to 4
Explanation:
Dwight and Walt are building model cars.
Let d = the number of models built by Dwight.
Let w = the number of models built by Walt.
Dwight builds 7 fewer models than 4 times the number Walt builds. This can be expressed as
d = 4w - 7 - - - - - - - - - 1
Dwight builds at most 9 models. This is expressed as
d lesser than or equal to 9
From equation 1
d = 4w - 7
4w = d + 7
w = (d+7)/4
Assuming Dwight built 9 models
w = (9+7)/4 = 4
Therefore,
Walt builds at most 4 models. It is expressed as
w lesser than or equal to 4
It is shown in the attached photo