From the present question, we know that the number of jars Anita filled times the number of nuts inside each jar will give the total amount of nuts Anita used.
If W is the total of nuts in lb units, w is the weight of nuts in a single jar and n is the number of Jars, we have the following relation:

Substituting the values which were given, we get the following:

To isolate n, to find its value, we multiply both sides by 4/3, to maintain equality.

From the solution above presented, we are able to say that Anita will be able to fill 8 jars with 3/4 lb of mixed nuts each