Adding rational numbers involves adding decimals and repeating decimals like 4.6666666..... Whole numbers on the other hand involves adding 7+6 which arent exactly decimals
Ab = (7x-6) → b = (7x-6)/a (1)
bc = (12-2x) → b = (12-2x)/c (2)
Since (1) = (2) → (7x-6)/a = (12-2x)/c OR a/c = (7x-6)/(12-2x) (3)
Multiply both numerators of (3) by the SQUARE of their respective denominators;
(a*c²)/c = (7x-6)(12-2x)²/(12-2x)
Now simplify:
ac = (7x-6)(12x-2x) or ac = -14x² + 96x - 72
Elapsed time from 105pm to 440am is 15 hours and 35 minutes.
We can’t help u if their is no instructions on what u need to do sorry