Question 8-9 sequences and series

Me write an equation for the interior angles of this triangle that uses the triangle sum theorem

Ifurniture stores having a weekend sale and is offering 20% discount on patio chairs and table the sales tax on furniture is 6.25 using function composition how can you represent the total amount a that you would need to pay for this furniture that cost x dollars

Which of the following are accepted without proof in a logical system? check all that apply.