Summary: The problem of topological classification of real algebraic curves is a classical problem in fundamental mathematics that actually arose at the origins of mathematics. The problem gained particular fame and modern formulation after D. Hilbert included it in his famous list of mathematical problems at number 16 in 1900. This was the problem of classifying curves of the sixth degree, solved in 1969 by D. A. Gudkov and G. A. Utkin [“Topology of curves of order 6 and surfaces of order 4 (to Hilbert’s 16th problem)” (Russian), Uchen. Zap. Gor’kovsk. Univ., 87, 4–214 (1969), see D. A. Gudkov, Transl., Ser. 2, Am. Math. Soc. 112, 9–14 (1978; Zbl 0434.14008) and G. A. Utkin, ibid. 123–140 (1978; Zbl 0434.14013)]. In the same place, Gudkov posed the problem of the topological classification of real algebraic curves of degree 6 decomposing into a product of two non-singular curves under certain natural conditions of maximality and general position of quotient curves. Gudkov’s problem was solved in [G. M. Polotovskii, Sov. Math., Dokl. 18, 1241–1245 (1977; Zbl 0392.14014); translation from Dokl. Akad. Nauk SSSR 236, 548–551 (1977)] and [I. M. Borisov and G. M. Polotovskii, “On the topology of planar real decomposable curves of degree 8” (Russian), Itogi Nauki Tekh., Ser. Sovrem. Mat. Prilozh., Temat. Obz. 176, 3–183 (2020; doi:10.36535/0233-6723-2020-176-3-18)]. At present, after a large series of works by several authors (exact references can be found in [Polotovskii and Borisov, loc. cit.]), the solution of a similar problem on curves of degree 7 is almost complete. In addition, in [T. V. Kuzmenko and G. M. Polotovskiĭ, “Classification of curves of degree 6 decomposing into a product of \(M\)-curves in general position”, Transl., Ser. 2, Am. Math. Soc. 173, 165–177 (1996)] a topological classification of curves of degree 6 decomposing into a product of any possible number of irreducible factors in general position, and in [A. B. Korchagin and G. M. Polotovskiĭ, St. Petersbg. Math. J. 21, No. 2, 231–244 (2010; Zbl 1206.14057); translation from Algebra Anal. 21, No. 2, 92–112 (2009)] a classification of mutual arrangements of \(M\)-quintics, a couple of lines were found.
The present paper is devoted to the case when the irreducible factors of the curve of degree 7 have degrees 3, 2, and 2, and is a continuation of the study begun in [V. A. Gorskaya and G. M. Polotovsky, “On the disposition of cubic and pair of conics in a real projective plane” (Russian), Zh. Sredn. Mat. Obshch. 22, No. 1, 24–37 (2020; doi:10.15507/2079-6900.22.202001.24-37)].