Zach has a basic cell phone plan that does not include texting. He is going to add a texting package to his cell phone plan. He has two choices of texting packages, A and B. Package A charges $0.15 per text with no monthly fees for the texting package. Package B charges $0.10 per text, but has a $10 monthly fee for the texting package. Write an equation that represents the total cost for each texting package if any amount of texts are sent. Be sure to define the variables you are using for your equation.