Question

AD =X, AE =X +3,DB=X+1,EC =X+10.FIND X IF DE IS PARALLEL TO BC

Answer 1

If DE is parallel to BC

then by B.P.T.

AD/BD=AE/EC

X/X+1=X+3/X+10

X(X+10)=X+3(X+1)

X^2+10X=X^2+X+3X+3

X^2+10X=X^2+4X+3

X^2+10X-X^2-4X=3

6X=3

X=3/6

X=1/2 OR 0.5