Express the following in the form of $(x+a{)}^2+b$.

$x^2-6x$

Express the following in the form of $(x+a{)}^2+b$.

$x^2+8x$

Express the following in the form of $(x+a{)}^2+b$.

$x^2-3x$

Express the following in the form of $(x+a{)}^2+b$.

$x^2+15x$

Express the following in the form of $(x+a{)}^2+b$.

$x^2+4x+8$

Express the following in the form of $(x+a{)}^2+b$.

$x^2-4x-8$

Express the following in the form of $(x+a{)}^2+b$.

$x^2+7x+1$

Express the following in the form of $(x+a{)}^2+b$.

$x^2-3x+4$

Express the following in the form of $a(x+b{)}^2+c$.

$2x^2-12x+19$