Question

How do I complete a square

Eg solve the equation x(squared) + 4x - 7 = 0
By completing the square

Answer 1

Step-by-step explanation:

${x}^{2} + 4x - 7 = 0$

Take -7 to the other side making it +7

Half the coefficient of x and square it

$\frac{1}{2} \times 4 = 2$

Square the answer

${2}^{2} = 4$

Join your answers

[

$(x + 2) - 4 = 7$

Take -4 to the other side making it +4

$(x + 2) = 7 + 4 \\

(x + 2) = 11

$

Square root both sides

$\sqrt{x + 2}= \sqrt{11}$

$x + 2 = \sqrt{11}$

Take +2 to the other side

$x = - 2 \ + or - \sqrt{11}$

$x = - 2 + \sqrt{11}$

or

$x = - 2 - \sqrt{11}$

This can be your answering surd form if required or in decimals