Question

# Explain how to complete the square for an expression of the form x²+bx.Add __ to x²+bx.

Explain how to complete the square for an expression of the form $$x^{2}+bx.$$
Add ? to $$\displaystyle{x}^{2}+{b}{x}.$$

To complete the square for an expression of the form $$\displaystyle{x}^{{2}}+{b}{x}$$, you need to divide the value of b by 2 and then square the result.
Therefore, to complete the square for an expression of the form $$\displaystyle{x}^{{2}}+{b}{x}$$, you need to add $$\displaystyle{\left(\frac{{b}}{{2}}\right)}^{{2}}\to{x}^{{2}}+{b}{x}.$$