#### Answer

$x = \frac{-1+\sqrt7}{4}$

#### Work Step by Step

Step 1: Use the Product of Cross Products
$4x = (2 + \sqrt7)(3 - \sqrt7)$
Step 2: Use FOIL to simplify the right side of the equation and simplify by combining like terms.
First + Outer + Inner + Last
$4x = 6 - 2\sqrt7 + 3\sqrt7 - 7$
$4x = -1 + \sqrt7$
Step 3: Divide both sides by 4 in order to isolate x.
$x = \frac{-1+\sqrt7}{4}$