WILL GIVE BRAINLIEST!!!! 50 POINTS. PLEASE HELP AND EXPLAIN!!!

let's find the area of the outer circle and the inside circle
the inside's circle area
A= π x 6²=36π
the outer's
A' = π x 4x²= 4πx²
A'-A=4πx²- 36π=160πcm² equivalent to x²- 9=40, so x²=49 implies x =sqrt(49)=7, x=7
ANSWER: x =7