Date: 7r^2 - 14r = -7 first we add to both sides of the equation number (+7) and we get => 7r^2 -14r +7 = 0 now we divide both sides with number (7) and we get r^2 -2r + 1 = 0 => this is the square of the binomial => (r - 1)^2 = 0
=> r - 1 = 0 when we add to both sides number (+1) we get final solution
=> r=1 This is only one solution of this quadratic equation.
