9) Which of the following is the solution to 7(x+9)^2+168=192 (1) x=-9+(2sqrt (42))/(7) (2) x=-9+(4sqrt (21))/(7) (3) x=9+(2sqrt (42))/(7) (4) x=9+(4sqrt (21))/(7)

To solve the equation $7(x+9)^{2}+168=192$, we first simplify the equation by subtracting 168 from both sides:<br /><br />$7(x+9)^{2}=24$<br /><br />Next, we divide both sides by 7:<br /><br />$(x+9)^{2}=\frac{24}{7}$<br /><br />Taking the square root of both sides, we get:<br /><br />$x+9=\pm\sqrt{\frac{24}{7}}$<br /><br />Simplifying the square root, we have:<br /><br />$x+9=\pm\frac{2\sqrt{42}}{7}$<br /><br />Finally, we solve for x by subtracting 9 from both sides:<br /><br />$x=-9\pm\frac{2\sqrt{42}}{7}$<br /><br />Therefore, the solutions to the equation are:<br /><br />(1) $x=-9+\frac{2\sqrt{42}}{7}$<br />(2) $x=-9-\frac{2\sqrt{42}}{7}$