Colleen S. answered 01/13/22
High School Algebra Teacher/Tutor
Hi Mark! Systems are equivalent if they can be formed from some combination of the original equations. For example, the second equation is 5d + 0.5e = 4. If we multiply the entire equation by 2, we get 10d + 1e = 8. This is the second equation in Letter F, and the first equation is exactly the same as the original first equation. So F would be equivalent to the original system. In Letter E, the original first equation is multiplied by 2 to get the new first equation. BUT, the new second equation is not correct. So F would not be equivalent. You can use this strategy to decide whether the other systems are equivalent or not.