The mass of two sacks of potatoes is 168 grams. One-eight of the mass of Sack A and three-quarter of the mass of Sack B is 76 grams. Write an equation to find the mass of Sack A.

The mass of two sacks of potatoes is 168 grams. One-eight of the mass of Sack A and three-quarter of the mass of Sack B is 76 grams. Write an equation to find the mass of Sack A.