Answer:
x= +4, -4
Step-by-step explanation:
If I'm not mistaken, you're given is x²-16=0 right?
So to extract the square root, just transpose all the constant term to the right side of the equation and all the terms with variable in it should remain in the left side.
x² - 16 = 0
x²=16
√x²=√16
x= +/-4
