If 5 tanβ = 4, then 5sinβ-2cosβ5sinβ+2cosβ=
(1)
5tanβ=4 ⇒ tanβ=45
∴ 5sinβ-2cosβ5sinβ+2cosβ=5tanβ-25tanβ+2 [dividing cosβ by Nr. and Dr.]
=5×45-25×45+2=26=13