Starting with x0=1x_0 = 1x0=1, use the iteration formula xn+1=6xn2+4\displaystyle x_{n+1} = \frac{6}{x_n^2 + 4}xn+1=xn2+46 three times to find an estimate for the solution to x3+4x=6x^3 + 4x = 6x3+4x=6.