Alittle while ago, a dolphin was swimming below sea level at -7 meters. now the dolphin is jumping at 0.5 meters. what does this mean?

Find the center and the radius of the circle with the equation: x^2-2x+y^2+4y+1=0?

Which is the correct first step in finding the area of the base of a cylinder with a volume of 26x cubic meters and a height of 6.5 meters? v=bh 6.5=b(26x) v=bh v=26pi+(6.5) v=bh v=26pi(6.5) v=bh 26pi=b(6.5)

How do i simply this radical expression?