How do you solve #30^ { 2} + x ^ { 2} = 36^ { 2}#?

1 Answer
May 7, 2017

Simplify, then take the square root. #x= +-6sqrt(11)#

Explanation:

First, simplify it.
#30^2=900# and #36^2=1296#

So now you have #900+x^2=1296#

Now, get the x by itself. You can do that by subtracting 900 from both sides.

#900-900+x^2=1296-900#
#0+x^2=396#
#x^2=396#

You would then have to take the square root of each side to make #x^2# just x. However, 396 is not a perfect square, so you would simplify it as much as you could if you didn't have a calculator:

#±sqrt(396)#
#=±sqrt(36*11)#
#=±sqrt(6*6*11)#
#=±6sqrt(11)#
#~~±19.9# (found with calculator)