21/84 in simplest form

Find the roots of the equation below. x^2 - 6 + 9 = 0

The graph below shows the height of a projectile t seconds after it is launched. if acceleration due to gravity is -16 ft/s2, which equation models the height of the projectile correctly?

The suare root of 9x plus 7 plus the square rot of 2x equall to 7