In the previous deck, we learned how to rewrite a quadratic expression by completing the square. Now, we'll use that skill to solve quadratic equations. This means finding the specific values of x that make the equation true.

Let's start with an equation we want to solve, for example, x squared plus 6x plus 5 equals 0. After completing the square, this equation can be rewritten as: open bracket x plus 3 close bracket squared, minus 4, equals 0.

To isolate the squared bracket in our example, which is 'open bracket x plus 3 close bracket squared, minus 4, equals 0', we need to get rid of the minus 4. We do this by adding 4 to both sides of the equation. This leaves us with 'open bracket x plus 3 close bracket squared equals 4'.

Now that we've isolated the squared part, our equation is 'open bracket x plus 3 close bracket squared equals 4'. The next step is to undo the square. The opposite, or inverse, of squaring something is to take its square root.