Answer:
24
Explanation:
Let Noah = x. I will write the equation in order of appearance with Noah first.
x + 3x + (3x + 5) + (3x + 12) + (x - 4) + 2(x-4) = 317
Distribute where needed and remove parentheses
x + 3x + 3x + 5 + 3x + 12 + x - 4 + 2x - 8 = 317
Collect like terms
13x + 5 = 317
Move the constant to the right of the equal sign and do the math
13x = 312
Divide both sides by 13
Noah sold 24 cookies