Answer :
a.
[tex]x^2=49 \\ \sqrt{x^2}=\sqrt{49} \\ |x|=7 \\ x=-7 \ \lor \ x=7 \\ \boxed{x=-7 \hbox{ or } x=7}[/tex]
b.
[tex]x^2-7=29 \ \ \ |+7 \\ x^2=36 \\ \sqrt{x^2}=\sqrt{36} \\ |x|=6 \\ x=-6 \ \lor \ x=6 \\ \boxed{x=-6 \hbox{ or } x=6}[/tex]
c.
[tex]4x^2=64 \ \ \ |\div 4 \\ x^2=16 \\ \sqrt{x^2}=\sqrt{16} \\ |x|=4 \\ x=-4 \ \lor \ x=4 \\ \boxed{x=-4 \hbox{ or } x=4}[/tex]
[tex]x^2=49 \\ \sqrt{x^2}=\sqrt{49} \\ |x|=7 \\ x=-7 \ \lor \ x=7 \\ \boxed{x=-7 \hbox{ or } x=7}[/tex]
b.
[tex]x^2-7=29 \ \ \ |+7 \\ x^2=36 \\ \sqrt{x^2}=\sqrt{36} \\ |x|=6 \\ x=-6 \ \lor \ x=6 \\ \boxed{x=-6 \hbox{ or } x=6}[/tex]
c.
[tex]4x^2=64 \ \ \ |\div 4 \\ x^2=16 \\ \sqrt{x^2}=\sqrt{16} \\ |x|=4 \\ x=-4 \ \lor \ x=4 \\ \boxed{x=-4 \hbox{ or } x=4}[/tex]