Chapter 1 - Section 1.3 - Algebraic Expressions - 1.3 Exercises - Page 34: 41

$ x - 4$

$Multiply$ $the$ $algebraic$ $expressions$ $using$ $a$ $Special$ $Product$ $Formula$ $and$ $simplify:$ $(\sqrt x + 2)(\sqrt x - 2)$ Use the Sum and Difference of Same Terms Product Formula: $(A+B)(A-B) = A^2-B^2$ $(\sqrt x + 2)(\sqrt x - 2) = (\sqrt x)^2 - 2^2$ Note: $(\sqrt x)^2 = x^{\frac{1}{2}\times \frac{2}{1}} = x^1 = x$ $= x - 4$