Какой ответ у него 8 7/10-5 3/4+6 1/5

8 7/10-5 3/4+6 1/5=
9 14/20-15/20+4/20=
8 34/20-15/20+4/20=
8 23/20

8 ⁷/₁₀ - 5 ³/₄ + 6 ¹/₅= 9 ³/₂₀
1/ 8 ⁷/₁₀ - 5 ³/₄ = ⁸⁷/₁₀ - ²³/₄ = ⁸⁷ˣ² ⁻²³ˣ⁵/₂₀ = ¹⁷⁴⁻¹¹⁵/₂₀ = ⁵⁹/₂₀
2/ ⁵⁹/₂₀ + 6 ¹/₅ = ⁵⁹/₂₀ + ³¹/₅ = ⁵⁹⁺³¹ˣ⁴/₂₀ = ⁵⁹⁺¹²⁴/₂₀ = ¹⁸³/₂₀ = 9 ³/₂₀