Hey there! :)
Since 2 4/5 is greater than 1/4, the answer is negative.
You can just subtract 2 4/5 and 1/4 and add the (-) sign
2 4/5 - 1/4
Change the fractions so they can have a common denominator: 20
2 4/5 = 2 16/20
1/4 = 5/20
2 16/20 - 5/20 = 2 11/20
Add the (-) sign → -2 11/20
Answer ⇒ -2 11/20
:)
All of the above are true
2. Angle Addition Postulate as they are adding both angles
3. 60 + 40 = m <ABC because it's a substitution
4. 100 = m <ABC as it is simplified already
5. Definition of obtuse angle
This is just about similar triangle
mn=2jl=22
mo=2lk=26
jk=2on=40