Respuesta :
[tex](5+x)(5-x)=7\\\\\text{use:}\ (a-b)(a+b)=a^2-b^2\\\\5^2-x^2=7\\\\25-x^2=7\ \ \ |-7\\\\18-x^2=0\\\\x^2-18=0[/tex]
[tex]Answer:\ \boxed{A=1;\ B=0;\ C=-18}[/tex]
[tex]Answer:\ \boxed{A=1;\ B=0;\ C=-18}[/tex]
