lean_workbook_plus_59348
ProvedSolutionIf is the number of purple socks that Jamal added, then $$\frac{18+x}{6+18+12+x}=\frac{18+x}{36+x}=\frac{3}{5} \implies 90+5x=108+3x \implies x=\frac{108-90}{5-3}=\boxed{\textbf{(B)}}~9.$
Preamble
import Mathlib.Analysis.Complex.Basic
Formal statement
theorem lean_workbook_plus_59348 (x : ℝ) (h₀ : 0 < x) (h₁ : (18 + x) / (6 + 18 + 12 + x) = 3 / 5) : x = 9 := by sorry
Source