Verified answer

A = (1/3 - 1/2) ÷ 5/36

  = (2/6 - 3/6) × 36/5

  = -1/6 × 36/5

  = (-1 × 36)/(6×5)

  = (-6×6)/(6×5)

  = -6/5

B = (3/5 × (-25/9) + 1)/(1 - 1/9)

  = ((-3×25)/(5×9) + 1)/(9/9 - 1/9)

  = ((-3×5×5)/(5×3×3) + 1)/(8/9)

  = ((-5/3) + 1) × (9/8)

  = (-5/3 + 3/3) × (9/8)

  = (-2/3) × (9/8)

  = (-2×9)/(3×8)

  = (-2×3×3)/(3×2×4)

  = -3/4