Answers:
5. x = 1
6. y = 11.5
Explanation:
For question 5, you can use power of a point which describes the relationship of two secants intersecting inside a circle. You get the formula:
AC * CD = BC * CE
You can substitute the values you are given to get:
2 * 4 = x * 8
This gives you x = 1
For question 6, you can use another formula in power of a point that describes two secants intersecting in the exterior of a circle. You get the formula:
GH * GJ = GI * GK
Using segment addition postulate, you get:
GJ = GH + HJ = 5 + 16 = 21
GK = GI + IK = 6 + y --> y + 6
Now, substitute into the equation from power of a point:
5 * 21 = 6 * (y + 6)
105 = 6 * (y + 6)
17.5 = y + 6
y = 11.5