Making a list can help you solve a math problem because it shows you the information you will be using.
Sally is 13 years old. Sally's brother Mark is twice as old as Sally. Sally's older sister Daffy is the sum of Sally and Mark's age. How old is Daffy?
making a list in this question tells you all of the different ages and lists them out in a row.
Answer:
a is 2.5
b is 1
gradient is rise over run
Answer:

Step-by-step explanation:
We can apply the distributive property then combine like terms for a simpler equation.

Hope this helped!