Question

State and prove Basic proportionality theorem. In ∆ABC, if DE ∥ BC, AD = x, DB = x − 2, AE = x + 2 and EC = x − 1,then using the above result, find the value of x.

Answer 1

For correct statement, given, to prove, figure and construction 

For correct proof 

In ∆ABC, DE ∥ BC 

⟹ AD/DB = AE/EC 

⟹ x/x−2 = x+2/x−1 

Solving, we get x = 4