Solve for a sqrt(a - b + c) = 3

[tex]\bold{\sqrt{a-b+c}=3 }[/tex]
[tex]\bold{(\sqrt{a-b+c)}^2=3^2 }[/tex]
[tex]\bold{ a-b+c=9 }[/tex]
[tex]\bold{ a=9+b-c }[/tex]