The last one will give the incorrect slope
Answer:

Step-by-step explanation:
I do not know if this is completely correct
Answer:
489.5 + m = 756.80 (the amount elias has, added to marks is equal to the total
(756.8- 489.5 = 267.30 which is the amount mark has.)
m= 267.3
the last option is the correct option
Step-by-step explanation:
What expression ? There isn’t one