Answer:
[tex](x-5)^{2} =64[/tex]
Step-by-step explanation:
[tex]x^{2}-39=10x[/tex]
[tex]x^{2}-10x=39[/tex]
[tex]x^{2} -10x+(-5)^{2}=39+(-5)^{2}[/tex]
[tex]x^{2} -10x+25=64[/tex]
