Find the value of the discriminant 3x^2-5x=2

Is the point (0, 8) on the x-axis or y-axis? how do you know?

At noon a tank contained 10cm water. after several hours it contained 7cm of water. what is the percent decrease of water in the tank?

Acentral angle measuring 160 degrees intercepts an arc in a circle whose radius is 4. what is the length of the arc the circle formed by this central angle? round the length of the arc to the nearest hundredth of a unit. a) 4.19 units b) 6.28 units c) 12.57 units d) 12.57 square units