The commutative property of 9+8=17 is 8+9=17 because the commutative property states that it doesn't matter the order of the number but as long as u get the same answer.
Remmeber you can do anything to an equaiton as long as you do it to btoh sides 5-6(a+2)=7+a distribute 5-6a-12=7+a add like terms -6a-7=7+a add 6a both sides -7=7+7a minus 7 both sides -14=7a divide by 7 -2=a a=-2
