How do you solve #x^{2} - 8= 0#?

3 Answers
Jim G.
May 23, 2018

#x=+-2sqrt2#

Explanation:

#"isolate "x^2" by adding 8 to both sides"#

#x^2=8#

#color(blue)"take the square root of both sides"#

#sqrt(x^2)=+-sqrt8larrcolor(blue)"note plus or minus"#

#rArrx=+-2sqrt2#

Bill Jorgensen
May 23, 2018

#x= +-2sqrt(2)#

Explanation:

#x^{2} - 8= 0#

first add 8 to both sides:

#x^{2}= 8#

now take the square root of both sides, remember you must use #+-# the square root on the right side:

#sqrt(x^{2})= +-sqrt(8)#

#x= +-2sqrt(2)#

Veddesh #phi#
May 23, 2018

#x=+-2sqrt2#

Explanation:

#color(blue)(x^2-8=0#

To, solve this, we need to isolate #x^2# in one side of the equation. To do that, we can add or subtract the same number in both sides of the equation.

Add #8# both sides

#rarrx^2-8+color(red)(8)=0+color(red)(8)#

#rarrx^2=8#

Now, take the square root of both sides,

#rarrsqrt(x^cancel2)=+-sqrt8#

#rarrx=+-sqrt8#

Now, take the prime factors of #8#

#rarrx=+-sqrt(underbrace(2*2)*2)#

#color(green)(rArrx=+-2sqrt2#

Remember that #+-# means plus or minus

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