I think you need to add a picture?
To solve the problem, substitute the given points for x in the given equation to get

Solving the three equations simultaneously, we have:
a = -3, b = 2 and c = -5
Therefore, the required equation is
Answer:
Tito have
textbooks in terms of x
Step-by-step explanation:
Rudy has 6 textbooks
We are given that Tito and Maria each have y textbooks
So, Tito has no. of books = y
Maria has no. of books = y
So, total number of textbooks = 6+y+y=6+2y
We are given that Rudy, Maria, and Tito have a total of x textbooks
So,6+2y=x
So, 2y=x-6

Hence Tito have
textbooks in terms of x
Opposite number is like 8 and -8. And absolute value is like -8 and 8 or 9 and 9. The absolute value is always positive.
Since he sold it for $75 more,
% Mark Up = Mark Up/ Cost Price x 100%
% Mark Up = 75 / 125 x 100% = 0.6 x 100% = 60%
Percent Mark Up = 60%
Hope this helps :)