For the following exercises, set up the augmented matrix that describes the situation, and solve for the desired solution.
A bag of mixed nuts contains cashews, pistachios, and almonds. Originally there were 900 nuts in the bag. $30 \%$ of the almonds, $20 \%$ of the cashews, and $10 \%$ of the pistachios were eaten, and now there are 770 nuts left in the bag. Originally, there were 100 more cashews than almonds. Figure out how many of each type of nut was in the bag to begin with.