I dont understand this matrix question, PLZ HELP!! ;(

You are responsible for designing a new city. you are inspired by pierre charles l'enfant, who laid out the streets of our nation's capital. numbered streets run north and south, and lettered streets run east and west. avenues are named after states, and they intersect the streets on a diagonal. the streets are parallel and the intersections form similar triangles. 18th st. is 454 meters long and the intersection of 18th and k st. is 207 meters from connecticut ave. if 19th st. and k st. is 385 meters from connecticut ave., what is the length of 19th st.?

Acd that is originally priced at $15.85 red-tagged for the sale. what is the sale price of the cd

What is r i 4.5+10r=-6.5 with work pls