What is true about the unknown length

Aphoto of a painting measured 13 x 17 inches the scale of the photo to the original painting is 1 inch to 3 inches. what is the size of this painting

Mr. and mrs. wallace have decided to buy a car for $21,600. they finance $15,000 of it with a 5-year auto loan at 2.9% arp. what will be their monthly payment be? a. $268.20 b. $268.86 c. $269.54 d. $387.16 (monthly car loan payment per $1,000 borrowed) i need !

On #16 : explain how factoring a trinomial, ax^2+ bx+ c, when a does not equal 1 different from factoring a trinomial when a = 1.