Answer:

Step-by-step explanation:
Explicit Arithmetic Formula: 
a₁ is 1st term in sequence
<em>d</em> is common difference
<em>n</em> is term number
Step 1: Find <em>d</em>
d = 8 - 2 = 6
Step 2: Plug in variables into formula

Answer:
slope intercept form is y=-2/3x+5
Work backwards..
30 helmet + 30 left = 60$
60 + 15 charity = 75$
75 + 25 music = 100$