Hello There!
The first one seems alright.
The second one it would be 1/2.
This is because half of the options have “R” on them.
There is a designated formula for this circle drawing. This is a secant-secant scenario, and in this case, the formula is:
CD(CD+X)=CB(CB+AB)
Plug the values in.
AB=42
BC=18
CD=4
4(4+x)=18(18+42)
Solve for x.
16+4x=1080
4x=1064
x=266
Your answer is C
Answer:

Step-by-step explanation:
Using the rule of exponents
⇔ 
Evaluating from the inside parenthesis outwards
= -
× -
=
, then
=
= 9² = 81 , then
= 