The fraction he added is 6/30, or 1/5.
I'm not 100% sure about the equation you want me to use but I did the work this way:
5/6+x/30=31/30 (the denominator has to equal 30 because you are adding. You need a common denominator which is why you need to change 5/6. We can label the numerator as a hidden value x)
25/30+x=31/30
You can then work backwards and basically subtract 25 from 31 and get 6; so x=6
Answer:

Step-by-step explanation:
points on the line:- (-4,-5)&(6,4)
slope= 4+5/6+4= 9/10
y-4=9/10(x-6)
y=9x/10-54/10+4
y=9/10 x-7/5
✄┈┈┈┈┈┈┈┈┈┈┈┈┈┈«
┍━━━━ ⋆⋅☆⋅⋆ ━━━━┑
hope it helps..
have a great day!!
┕━━━━ ⋆⋅☆⋅⋆ ━━━━┙
Answer:
(a)8.0mg
(b)36.87 hours
(c)-0.168
Step-by-step explanation:
The amount of Valium in that person's bloodstream at any time can be modeled with the exponential decay function
(t in hours)
(a)After 12 Hours

(b)If A(t)=5mg
Then:

(c)

the answer to this problem is 4