I have the answer (0.6) but I need help with explaining why

Which expression demonstrates the use of the commutative property of addition in the first step of simplifying the expression (-1+i)+(21+5i)+0

1.3.4 practice : modeling: solving linear equations in this assignment, you may work alone, with a partner, or in a small group. discuss the results of your work and/or any lingering questions with your teacher. your assignment: road trip you're taking a scenic road trip down ca-highway 1 from san jose, california, to los angeles. you plan to split the drive into two days, stopping for one night. choose one town to stop in, and find the driving distance for the second day. 1. circle the town you chose to stop in. (1 point) santa barbara: an image of palm trees san luis obispo: an image of a church 2. why did you choose this town? (1 point) 3.what do you know? .what do you want to find out? .what kind of answer do you expect? define the variable. 4. what is the variable x for this problem? (1 point) write the equation. 5. write an equation showing that the distance traveled on the first day plus the distance traveled on the second day is equal to 425 miles. (4 points: 2 points for each side of the equation) isolate the variable. 6. what inverse operation do you need to perform on both sides to isolate x in the equation? (2 points: 1 point for the correct number, 1 point for the correct operation) solve the equation. 7. solve the equation for x. interpret the answer in terms of the problem. (2 points: 1 point for the solution, 1 point for the interpretation) check your solution. 8. to confirm that your answer is correct, add the two days' distances. this should equal the total distance from san jose to los angeles. show your work as an equation. (3 points: 1 point for the setup, 2 points for the correct answer)

Need with son's homework i will give 30 ! show work daniel's house is located b miles from his school. the swimming pool is 3 miles farther from his school. his dr. office is 4 miles less than twice the distance from home to daniel's school. a. write an expression that shows the distance from daniel's house to the swimming pool. b. write an expression that shows the distance from daniel's house to his dr's office c. if b=3, is the swimming pool or dr's office closer to daniel's house? how much closer