Answer:
y = 12
Explanation:
∵ m∠ABC = 40
∵ BD ray is the bisector of ∠ABC
∴ m∠ABD = m∠CBD = 20
In 2 Δ BAD and BCD:
∵ m∠BAD = m∠BCD = 90°
∵ m∠ABD = m∠CBD = 20°
∵ BD is a common side in the two triangles
∴ ΔABD congruent to ΔCBD⇒(AAS)
∴ AD = CD
∴ 3y + 6 = 5y - 18
∴ 5y - 3y = 6 + 18
∴ 2y = 24
∴ y = 24/2 = 12