The property illustrated by the expressions 8 + [6 + (-7)] = (8+6) + (-7) and 12 + 6 = 18 is the associative property of addition. If 4r + 20 (7h) =36, and r=5h, then 20h + 20 (7h) =36 illustrates substituting 5h for r in the original equation. If x+4 = 15, then x+4 – 4 = 15 – 4 illustrates subtracting 4 from both sides of the original equation to isolate the variable x.

1. Reviewer in Math I<br />Identify the property illustrated by each expression:<br />8 + [6 + (-7)] = (8+6) + (-7) <br />12 + 6 = 18 <br />If 4r + 20 (7h) =36, and r=5h, then 20h + 20 (7h) =36 <br />If x+4 = 15, then x+4 – 4 = 15 – 4.<br />4r + 20 (7h) = 4r + 20 (7h) <br />Factor completely:<br />1. 45a3b2c – 15a2b3c + 25a2b4c3

2. 2. 144mn4p2 + 96m2n3p4 – 72m3n2c3