Which human action can change the course of a waterway? 1.polluting 2.digging canals 3.mining coal 4.making tunnels for railroad passage

Evaluate the following expression 1/3^2

What is the difference between the equations of a vertical and a horizontal line?

If 30 lb of rice and 30 lb of potatoes cost ? $27.60? , and 20 lb of rice and 12 lb of potatoes cost ? $15.04? , how much will 10 lb of rice and 50 lb of potatoes? cost?