Answer:
The number is 25
Step-by-step explanation:
we have
[tex]x^{2} -10x=7[/tex]
we know that
[tex]10/2=5[/tex]
so
Adds [tex]5^{2}[/tex] both sides
[tex]x^{2} -10x+5^{2}=7+5^{2}[/tex]
[tex]x^{2} -10x+25=7+25[/tex]
[tex]x^{2} -10x+25=32[/tex]
Rewrite as perfect squares
[tex](x-5)^{2}=32[/tex]
