Question 208286
Generally there are three ways to solve quadratic equations:
1) Quadratic formula
2) Factoring
3) Completing the square
The first two are usually easier and they both require that the equation be in the form: {{{ax^2 + bx +c = 0}}}. So it is usually a good idea to simplify both sides and then get one side equal to zero. This is where we will start.
{{{(x+6)^2=2x^2+21x+50}}}
Simplify. Start by multiplying {{{(x+6)^2}}} or {{{(x+6)(x+6)}}}. Use FOIL or the perfect square pattern: {{{(a + b)^2 = a^2 + 2ab + b^2}}}.
{{{x^2 + 12x + 36 = 2x^2 + 21x +50}}}
Get one side equal to zero. Since it is a little easier if the squared term has a positive number in front of it, I will subtract {{{x^2 + 12x + 36}}} from both sides:
{{{0 = x^2 + 9x + 14}}}
Now we have the equation in the form we need for either the Quadratic formula or the Factoring method. If you are up on your factoring, you will notice that the right side factors easily. So this is the method we will use here. (Feel free to use the Quadratic formula if you like.)
{{{0 = (x + 7)(x + 2)}}}
In order for this product to be zero, one of the factors must be zero. This means:
{{{x + 7 = 0}}} or {{{x + 2 = 0}}}
Now we have two simple equations to solve. Subtracting 7 from both sides of the first equation and subtracting 2 from both sides of the second equation we get:
{{{x = -7}}} or {{{x = -2}}}
which are the solutions to the original equation.