## Elementary Algebra

$21\sqrt5 - 11\sqrt6$
RECALL: The distributive property states that for any real numbers a, b, and c: $ac+bc=(a+b)c$ Regroup the terms to obtain: $=(7\sqrt5+14\sqrt5)+(-9\sqrt6-2\sqrt6)$ Use the distributive property to simplify: $=(7+14)\sqrt5 + (-9-2)\sqrt6 \\=(21)\sqrt5 + (-11)\sqrt6 \\=21\sqrt5 - 11\sqrt6$