Question 50522
1. Zero Property: any thing that times 0 will equal to 0.
2. Associative Property (of multiplication):  the order that numbers are grouped in addition and multiplication doesn't affect the result. 
3.well...is it 3t+2r = 2r+3t istead of 3t+2r-2r+3t? well.. if it is... then it's Commutative Property (of addition): switching the order of two numbers being added or multiplied doesn't change the result.