Using significant digits calculate (3.89 + 0.046) x 7.221

What is the range of the data below? .8090100

David must install fencing around a lot that is shaped like a right angle.the side of lot that runs east-west is 200 ft long.the side of the lot runs north-south is 125 ft long.calculate how many feet of fencing he will need to surround the entire lot.

Solve for x and y: 217x + 131y = 913; 131x + 217y = 827