5 целых 2/3×(12-x)=1 целая 5/12

5²/₃×(12-x)=1⁵/₁₂12-x = 1⁵/₁₂ : 5²/₃12-x = ¹⁷/₁₂ : ¹⁷/₃12-x = ¹⁷/₁₂ × ³/₁₇12-x = ¹⁷ˣ³/₁₂ₓ₁₇12-x = ³/₁₂12-x = ¹/₄-x = ¹/₄ - 12-x = ¹/₄ - 11⁴/₄-x = - 11³/₄x = 11³/₄x= 11,75