1)
(х + ⁴/₂₁ ) - ⁴/₁₅ = ¹⁶/₃₅
х + ⁴/₂₁ = ¹⁶/₃₅ + ⁴/₁₅
х + ⁴/₂₁ = ⁽¹⁶ˣ³⁺⁴ˣ⁷⁾/₁₀₅
х + ⁴/₂₁ = ⁷⁶/₁₀₅
х= ⁷⁶/₁₀₅ - ⁴/₂₁ = ⁽⁷⁶⁻⁵*⁴⁾/₁₀₅ = ⁵⁶/₁₀₅
х= ⁸/₁₅
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(⁸/₁₅ + ⁴/₂₁) - ⁴/₁₅ = ¹⁶/₃₅
⁽⁷*⁸ ⁺ ⁴*⁵⁾/₁₀₅ - ⁽⁴*⁷⁾ /₁₀₅ = ¹⁶/₃₅
⁷⁶/₁₀₅ - ²⁸/₁₀₅ = ¹⁶/₃₅
⁴⁸/₁₀₅ = ¹⁶/₃₅
¹⁶/₃₅=¹⁶/₃₅
2)
(х - ⁸/₁₉) - ⁴/₅₇ = ²/₃
х - ⁸/₁₉ = ²/₃ + ⁴/₅₇
х - ⁸/₁₉ = ⁴²/₅₇
х - ⁸/₁₉ = ¹⁴/₁₉
х = ¹⁴/₁₉ + ⁸/₁₉ = ²²/₁₉
х = 1 ³/₁₉
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(1 ³/₁₉ - ⁸/₁₉) - ⁴/₅₇ = ²/₃
⁽¹⁴*³ ⁻⁴ ⁾/₅₇ = ²/₃
³⁸/₅₇ = ²/₃
²/₃ = ²/₃
3)
(х - ⁸/₉) + ³/₈ = ¹⁹/₃₆
х - ⁸/₉ = ¹⁹/₃₆ - ³/₈
х - ⁸/₉ = ⁽²*¹⁹ ⁻ ⁹*³⁾/₇₂
х - ⁸/₉ = ¹¹/₇₂
х = ¹¹/₇₂ + ⁸/₉ = ⁽¹¹ ⁺⁶⁴⁾ / ₇₂ = ⁷⁵/₇₂ = ²⁵/₂₄
х=1 ¹/₂₄
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(1 ¹/₂₄ - ⁸/₉) + ³/₈ = ¹⁹/₃₆
(⁷⁵/₇₂ - ⁶⁴/₇₂) + ²⁷/₇₂ = ¹⁹/₃₆
³⁸/₇₂ = ¹⁹/₃₆
¹⁹/₃₆=¹⁹/₃₆