Answer:
x=12cm
Step-by-step explanation:
PA ×PB=PT^2
4×(4+x)=(8)^2
16+4x=64
4x=64-16
4x=48
x =12
(whole secant) x (external part) = (tangent)^2
(4+x) * 4 = 8^2
Distribute
16+4x = 64
Subtract 16 from each side
4x = 48
Divide each side by 4
4x/4 = 48/4
x = 12
