Can you break down the solution for me for this math problem: Grayson recycles cans and bottles for money each week. An aluminum can is worth two cents and a plastic bottle is worth three cents. She drinks three aluminum cans of soda and five plastic bottles of water a week. How many cents does Grayson earn from recycling in a four-week month?
Grayson earns 2 * 3 = 6 cents from soda cans a week.
She earns 3 * 5 = 15 cents from water bottles a week.
Thus, she earns 6 + 15 = 21 cents from recycling each week.
In a four week month, she earns 21 * 4 = 84 cents from recycling.