So, these are actually pretty simple once you learn the equality used to solve for "x" and when to implement this method. You can use this equality to solve for a segment "x" anytime that two secant lines cutting through a circle come from the same point outside the circle.
Secant: by geometric definition is just a straight line that cuts a curve into multiple pieces.
I did one of them for you hopefully you can use my work for "a" to help you solve for "b".
For a. I got x=7.
48 ÷ 80 = .6
60/100 = 6/10 = 3/5
3/5 of every gallon is green
Answer:(a)
Step-by-step explanation:
Given
Principal amount 
Rate of interest 
Time 
Simple interest in 5 years



So total amount after five years
1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 x 200