In Fig. 4.72, . If OA = 3x – 19, OB = x – 4, OC = x – 3 and OD = 4, find x.

AO/OC=BO/OD


3X-19/X-3=X-4/4


(x-3)(x-4)=4(3x-19)


X2 -4x-3x+12=12x-76


X2 -7x+12-12x+76=0


X2 -19x+88=0


X2 -11x-8x+88=0


X(x-11)-8(x-11)=0


(x-11)(x-8)=0


x-11=0


x=11


or x-8=0


x=8


x=11 or 8


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