Pilar and her sister Marisol live near the beach. Pilar has 80 seashells in her collection when Marisol started collecting seashells. Marisol started with zero seashells in her collection. ● Pilar adds 10 seashelles to her collection each week for x weeks.
● Marisol adds 20 seashells to her collection each week for x weeks. Please write and solve the equation that represents the situation when the number of seashells in Marisol's collection is the same as the number of seashells in Pilar's collection. Please make sure to show every step in solving this equation. THANK YOU FOR YOUR TIME.