Please solve the questions 30 points I really need this

What number should be added to both sides of the equation to complete this square? x^2-10x=7

Atriangle with all sides of equal length is a/an triangle. a. right b. scalene c. equilateral d. isosceles

Aball is thrown from a height of 139 feet with an initial downward velocity of 15 ft/s. the ball's height h (in feet) after t seconds is given by the following. h=139-15t-16t^2 how long after the ball is thrown does it hit the ground? round your answer(s) to the nearest hundredth. (if there is more than one answer, use the "or" button.) t =