What are the solutions to the equation x2 − 1 = 399? A. X=20 and x=-20 B. X=200 and x=-200 C. X=400 and x=-400 D. X=398 squared and x=-398 squared
Mathematics · Middle School · Wed Jan 13 2021
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Given the numerical equation:
x^2 - 1 = 399
Determine the solution of the equation:
Solution:
In order to determine the solution of the equation, the first step is to transpose -1 to the other side of the equation, hence it must be taken to note that in transposing a number, the sign changes.
x^2 - 1 = 399
x^2 = 399 + 1
x^2 = 400
Take the square root of both sides in order to determine the value of x.
(x^2)^½ = (400)^½
x = 20
x = -20
Final answer:
x = 20
x = -20