Answer:
[tex] \sqrt{8} = 2 \sqrt{2} [/tex]
Step-by-step explanation:
In the equation we must first move 4 to the other side and change its sign
x^2 + 4 = 12
x^2 = 12 - 4
x^2 = 8
Then we find x:
x =
[tex]x = \sqrt{8} = \sqrt{2 \times 2 \times 2} = \sqrt{ {2}^{2} \times 2 } = 2 \sqrt{2} [/tex]