Answer: the final mass of the solid is 176 grams.
Step-by-step explanation:
The "change" between two quantities, one initial Qi and one final Qf is defined as:
Change = Qf - Qi.
In this case, the quantity is mass, and we know that the initial mass is 260 grams.
And we also know that the change is -84 grams.
Then we have the equation:
Qf - 260 g = -84g
Qf = -84g + 260g = 176g
So the final mass of the solid is 176 grams.
