In Fig. 4.243, the value of x for which is

Given in ΔABC, DE || AB.


We know that basic proportionality theorem states that if a line is drawn parallel to one side of a triangle to intersect the other two sides in distinct points, then the other two sides are divided in the same ratio.


Then



(x + 3) (3x + 4) = x (3x + 19)


3x2 + 4x + 9x + 12 = 3x2 + 19x


19x – 13x = 12


6x = 12


x = 2 cm

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