Question

Select the correct answer. What are the solutions to the equation x2 − 1 = 399?

Answer 1

Step-by-step explanation: well what we can do so far is this: x2-1=399

x2+1=399+1

So now that we have x2 by itself, the equation will look something like this

x2=400

because its x2 AND NOT x1, we will have to take the SQUARE ROOT.

x=±√400

x= either positive 20 or -20!

Answer 2

x= 200

Explanation:

(200)2 - 1 = 399