Answer:
Perpendicular...They have opposite slopes
Step-by-step explanation:
You could put,
19
+ 6
———
25
Then write,
19+6=25
Step-by-step explanation:
From the statement:
M: is total to be memorized
A(t): the amount memorized.
The key issue is translate this statement as equation "rate at which a subject is memorized is assumed to be proportional to the amount that is left to be memorized"
memorizing rate is
.
the amount that is left to be memorized can be expressed as the total minus the amount memorized, that is
.
So we can write

And that would be the differential equation for A(t).