If x² - 64 = 0 then x = ?

-------------------------------------------------------

answers:
Puzzling say: Original equation:
x² - 64 = 0

Factor the left as a difference of squares:
(x + 8)(x - 8) = 0

By the zero product rule, if ab=0 then a=0 or b=0:
x + 8 = 0
x = -8
Or
x - 8 = 0
x = 8

Answer:
x = ±8

You can also shortcut the process using x² = 64, but you must remember that there are two solutions to that equation:
x² = 64
√(x²) = √64
|x| = 8
x = ±8
-
Iggy Rocko say: x^2 - 64 = 0
x^2 = 64
x = 8 or x = -8
-
Como say: x = ± 8
-
David say: The value of x is - or + 8
-
Jeffrey K say: 8 or -8
-
Johnathan say: x = +/- 8. Just factor the left as a difference of squares or add 64 to both ends, then take the square root of them. If you do the latter, account for BOTH positive and negative answers.
-
Krishnamurthy say: x = ± 8
-
leeceve say: 0 + 64 = 64

Square root of 64 = 8

x = 8

Solve algebra problems by starting at the back of the equation and using opposite operations to move towards the front.
-
Midnight O. say: 8
-
llaffer say: x² - 64 = 0

Add 64 to both sides:

x² = 64

Square root both sides:

x = ± 8
-
Lindsay say: x2-64=0
add 64 to both sides to get
x2=64
sqaure root both sides
x=8
-
Bill-M say: Add 64 to both sides.
x² = 64
Take the Square boot of both Sides.
X=8
-
conley39 say: 8 or -8
-