The cost of a mirror is directly proportional to the square of its width. A mirror of width 40 cm costs $24. Find the cost of the mirror if the width is doubled please answer fast

Last one and the bottom answer choice is y=(x-4)^2+1 you guys!

The figure shows triangle def and line segment bc, which is parallel to ef: triangle def has a point b on side de and point c on side df. the line bc is parallel to the line ef. part a: is triangle def similar to triangle dbc? explain using what you know about triangle similarity. part b: which line segment on triangle dbc corresponds to line segment ef? explain your answer. part c: which angle on triangle dbc corresponds to angle f? explain your answer. asap

Do xuan nam isgoing to invest $1000 at a simple interest rate of 4% how long will it take for the investment to be worth $1040?