Question

How do you solve `x^2-4x=10` by completing the square?

Answer 1

Solution is x=2`+-sqrt14`

To make a perfect square on the left side, take half the coefficient of x and then square it. Here half of -4 is -2 and its square would be 4. Now add this number on both sides of the equation. On the left side it would now be a perfect square.

`x^2 -4x+4= 10+4`

`(x-2)^2 =14`

x-2=`+-sqrt14`

x=2`+-sqrt14`