How can i use substituition to show that 9+ 6(10-7x) is equivalent to 69-42x

Roger and natalie travel in similar cars. roger's car drives the two miles to school in 7.5 minutes. natalie drives the same distance in the opposite direction but in only 6.5 minutes. what is true of their velocities?

Turner's mom measured his room to see how long the wallpaper border needed to be. if two walls are 15 feet long and two walls are 12 feet long, how long should the strip of border be cut?

You paint a 1/2 of a wall in 1/4 hour. how long will it take you to paint one wall