Question

1. 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 seashells to her collection each week for x weeks.
• Marisol adds 20 seashells to her collection each week for x weeks.
(a) Write an inequality to represent the situation when the number of seashells in Marisol's collection is greater than the number of seashells in Pilar's collection.
(b) Solve the inequality in part (a) for the x. Show your work and explain your answer.

Answer 1

Answer:

a. 20x > 10x + 80

b.  •20x > 10x + 80

• Subtract 10x from both sides: 20x -10x > 10x + 80 - 10x

• Simplify: 10x > 80

• Divide both sides by 10:   10x/10 > 80/10

• Simplify: x > 8

Step-by-step explanation:

10x + 80 = number of seashells Pilar has.

20x = number of seashells Marisol has.  

answer for a:  20x > 10x + 80

answer for b: 20x > 10x + 80

• Subtract 10x from both sides: 20x -10x > 10x + 80 - 10x

• Simplify: 10x > 80

• Divide both sides by 10:   10x/10 > 80/10

• Simplify: x > 8