Explanation:

Given : AD=4 cm,DB=(x−4) cm,AE=8 cm and EC=(3x−19) cm.

To Find : x

We know that, by BPT(Basic proportionality theorem)

DB

AD

= ECAE(x−4)4

= (3x−19)8

4(3x−19)=8(x−4)

12x−76=8x−32

Solving, we get x=11 cm

Given : AD=4 cm,DB=(x−4) cm,AE=8 cm and EC=(3x−19) cm.

To Find : x

We know that by BPT(Basic proportionality theorem)

DB AD = EC AE

(x−4)4 = (3x−19)8

4(3x−19)=8(x−4)

12x−76=8x−32

Solving, we get x = 11 cm