help with solving (x + 3)(x + 4) / 2 = 24 for x!

Could someone show me step by step how to solve this problem? I'm stuck on the division and the foil method to solve for x.

(x+3)(x+4)=24
_________
2

aacr7789 said:

Could someone show me step by step how to solve this problem? I'm stuck on the division and the foil method to solve for x.

(x+3)(x+4)=24
_________
2

Click to expand...

multiply by 2 both sides to get:

(x+3)(x+4) = 48

Now use FOIL to expand the left-hand side

Then reduce the equation to get a "quadratic" equation.

Solve the quadratic equation.

If you are still stuck - write back showing your work in detail - so that we know where to begin to help you.

Ok- thank you- so here's where I'm stuck-
x^2+4x+3x+12=48
x^2+7x-36=0
What's next? I cannot figure out where to go from here!

\(\displaystyle x^{2}+7x-36=0\)

Since this does not factor nicely, use the quadratic formula. Plug and chug.

You can also complete the square.

I'm not sure how to do this- Could you show me an example using the quadratic formula and completing the sqare? Thanks!

Are you saying that your teacher did not cover the quadratic formula?

Memorize the quadratic formula, or else learn the method of completing the square.

General form of a quadratic equation:

\(\displaystyle ax^2+bx+c=0\)

Solve for x, by completing the square (I'll spare you the details). The following is known as the quadratic formula:

\(\displaystyle \boxed{x=\frac{-b\pm\sqrt{b^2-4ac}}{2a}}\)

Now "plug and chug" as Galactus told you.

In the equation \(\displaystyle x^2+7x-36=0\),

\(\displaystyle a=1, b=7, c= -36\)