How should I solve this equation, please. Can the positive solution x be represented precisely by a,b, and c? If not, are there some approximations to solve the problem?
[\begin{array}{l} \Gamma \left( {n,\frac{x}{{{\varphi _1}}}} \right) + \Gamma \left( {n,\frac{x}{{{\varphi _2}}}} \right) - \Gamma \left( {n,\frac{x}{{{\varphi _3}}}} \right) - \Gamma \left( {n,\frac{x}{{{\varphi _4}}}} \right) = 0;\\ {\varphi _1} = a + b + c;\\ {\varphi _2} = c;\\ {\varphi _3} = a + c;\\ {\varphi _4} = b + c;\\ 0 < a \ll b,0 < a \ll c;\\ n \in {Z^ + }n > 50\\ x = ? \end{array}]