Question

Eric was rock climbing. At one point, he stopped and climbed straight down 2 1/2 METERS

. Then he climbed straight up 6 3/4 meters
Eric was wondering what his change in elevation was after these two moves.

Answer 1

Bi did it on Khan academy

Explanation:

Answer 2

`+4(1)/(4)` meters

Explanation:

Let's take climbing down as "negative" and climbing up as "positive". Now, we can simply use the numbers and signs to find the change in elevation.

• 
  `2(1)/(2)` meters down means
  `-2(1)/(2)`
• 
  `6(3)/(4)`meters up means
  `+6(3)/(4)`

So, now we have:
`-2(1)/(2)+6(3)/(4)\\=-(5)/(2)+(27)/(4)\\=(-5(2)+27)/(4)\\=(-10+27)/(4)\\=(17)/(4)=4(1)/(4)`

Eric's elevation changed
`4(1)/(4)` meters above. So after the 2 moves, he is up by
`4(1)/(4)` meters.