Y+y+2=18 me 8 th grade 45points

Marquise has 200 meters of fencing to build a rectangular garden. the garden's area (in square meters) as a function of the garden's width w w (in meters) is modeled by: a ( w ) = − w 2 + 1 0 0 w a(w)=−w 2 +100w what side width will produce the maximum garden area? meters

How is this equation completed? i cannot find any examples in the book.

Two corresponding sides of two similar triangles are 3cm and 5cm. the area of the first triangle is 12cm2. what is the area of the second triangle?