Final answer:
The expression as provided cannot be simplified without correcting typographical errors or adding necessary parentheses. If solving for x is desired, a graphing calculator can be used to find the zeroes, with one solution being x=0.027 atm.
Step-by-step explanation:
The simplified form of the expression x + 8/3x + 7 + x +7/x+4 is not clear due to potential typographical errors or missing parentheses. If the intention is to simplify the expression as it is, each term is already in its simplest form, and they cannot be combined without common denominators for the fractional parts.
However, if the goal is to find a common solution for x across different equations or expressions, a graphing calculator could indeed be used to visualize and find the zeroes of the function that arises from setting the sum of the given terms equal to zero. In applying the zero function, one possible solution presented is x=.027 atm, which could indicate a root for the underlying equation if correctly derived.
Please ensure that the expression provided is accurate and includes all necessary parentheses for proper guidance on simplification or solving for x. Additionally, the mention of the 'quadratic formula' and 'degree three equation' implies there might be an equation involved rather than just an expression to simplify, so please clarify.