Question

What number should be added to complete the square of the following expression?

Answer 1

To calculate the number that must be added to make the expression:

`x^2-11x`
`\begin{gathered} x^2-11x \\ b^2=4ac \\ \text{from the equation:} \\ a=1\text{ , b= -11 , c= x} \end{gathered}`
`\begin{gathered} b^2=4ac \\ (-11)^2=4(1)(c) \\ 121=4c \\ c=(121)/(4) \end{gathered}`

Therefore the number that must be added to make the expression a perfect square is 121/4