What is the slope of 4y + 8x + 2 = 0?

Jackie purchased 3 bottles of water and 2 cups of coffee for the family for $7.35. ryan bought 4 bottles of water and 1 cup of coffee for his family for 7.15. how much does each bottle of water cost? how much does each cup of coffee cost?

When only separate discreet points are graphed it is called?

What is the rate of change of a line that passes through (2,-5) and (6,-2)?