In the given figure XYZ is a secant and ZT is a tangent. What is the value of x.

9 5 8 7

5

We know that,  PA × PB = PT2 We have, ZT = 6 cm, ZY = 4 cm and YX = x cm  = ZX × ZY = ZT2 = 4 × (YZ + XY) = 62 = 4 ×  (4 + x) = 36  = 4 + x = 9  = x = 5