Question

value: 7
solve the quadratic by taking square roots. write your answer with no spaces as x=a,-a where a and -a are the values you found when solving. round to the nearest tenth.
$2x^2 - 9 = 121$

Explanation:

Step1: Isolate the $x^2$ term

Add 9 to both sides:
$2x^2 = 121 + 9$
$2x^2 = 130$

Step2: Solve for $x^2$

Divide both sides by 2:
$x^2 = \frac{130}{2}$
$x^2 = 65$

Step3: Take square roots

Take square root of both sides:
$x = \pm\sqrt{65}$

Step4: Round to nearest tenth

Calculate and round:
$\sqrt{65} \approx 7.8$
So $x=7.8,-7.8$

Answer:

x=7.8,-7.8