Answer
a) 497
b) 497
c) They are equal by the commutative property of addition.
Work Step by Step
a) Tulsa to Dallas is 258 miles. Dallas to Houston is 239 miles. To find the total distance from Tulsa to Houston, we add the two distances to get $258+239=497$.
b) Houston to Dallas is 239 miles. Dallas to Tulsa is 258 miles. To find the total distance from Houston to Tulsa, we add the two distances to get $239+258=497$.
c) We notice that in these first two parts, $258+239=239+258$. This is called the commutative property because we can change the order of the two terms being added together without changing the sum.