Answer: 4
Step-by-step explanation:
Given
PA=6, PD=4, BE=5
We know, If PEB is a secant that intersects the circle at E and B and PA be a tangent at A, then
[tex]PA^2=PE\cdot PB[/tex]
Substitute the given values
[tex]\Rightarrow 6^2=(PE+BE)\cdot(PE)\\\Rightarrow 36=(PE+5)\cdot(PE)[/tex]
Take [tex]PE=x[/tex]
[tex]\Rightarrow 36=x^2+5x\\\Rightarrow x^2+5x-36=0\\\Rightarrow x^2+9x-5x-36=0\\\Rightarrow (x+9)(x-4)=0\\\Rightarrow x=-9,4[/tex]
Discard [tex]x=-9[/tex]
[tex]\therefore PE=4[/tex]
