Q.

In the given figure, DE  BC, AE = a units, EC = b units, DE = x units and BC = y units. Which of the following is true

1 x=a+bay  
2 y=axa+b  
3 x=aya+b  
4 xy=ab  

Ans.

(3)

As DEBC

 AEAC=DEBC  [From BPT]

aa+b=xy

x(a+b)=ayx=aya+b