Answer:
[tex]x = - \: 12.55 \: or \: x = 12.55[/tex]
Step-by-step explanation:
We want to solve for x in
[tex] {x}^{2} + 4.7^{2} = 13.4^{2} [/tex]
We group constants on the right to get:
[tex]{x}^{2} = 13.4^{2} - {4.7}^{2} [/tex]
We apply difference of two squares
[tex]{x}^{2} = (13.4 - {4.7})(13.4 + 4.7)[/tex]
[tex] {x}^{2} = 157.47[/tex]
[tex]x = \pm \sqrt{157.47} [/tex]
[tex]x = \pm \: 12.55[/tex]