(3/4)^50×(4^50+12^50/3^50+9^50)
=(3/4)^50×[4^50+(3×4)^50]/[3^50+(3×3)^50]
=(3/4)^50×4^50×(1+3^50)/[3^50×(1+3^50)]
=3^50/4^50×4^50/3^50
=1