Find the zeros of y=x^2-4x-9 by completing the square

The sum of the speeds of two trains is 720.2 mph. if the speed of the first train is 7.8 mph faster than the second train, find the speeds of each.

Edith is shopping for a new leather couch. jordan’s furniture has one that costs $3,000. however, this weekend she can get a 15% discount. how much money will edith save if she buys the couch this weekend? a $15b $2,550c $45,000d $450

Allen's goal is to have between 1,500 and 1,600 bottles in his collection. write and solve a compound inequality to determine the number of weeks it will take allen to reach his goal. show your work. *