The main purpose of this note is to give a proof of the fact that the Toda brackets ν, σ, ν and ν, η, σ are not trivial. This is an affirmative answer of the second author's Conjecture (Determination of the P -image by Toda brackets, Geometry and Topology Monographs 13 (2008), 355-383). The second purpose is to show the relation ν7ω15 = ν7σ10κ17 in π 731 .