What's the value of the underlined digit 540.72 the underlined digit is 5

1.)if r=2x³+4x²–x–6 and s=x–2.what is r/s? 2.)find the quotient when (x³-6x²+2x+8)ids divided by (x-3) 3.)what must be multiplied to (x²+2+1)to get (x⁴+x³+x²+3x+2)? 4.)if a square has a perimeter of (2x–48)meters,what expression represent its area? 5.)suppose the area of a rectangle is (6x²–7x+14)square units if its width is (2x–5)units, what expression represent its length? how about its perimeter?