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.
1/2 would be in between 0 and 1. The fraction 4/2 is actually 2, so it would just be plotted on the number 2 on the number line. 5/2 is reduced to 2.5, therefore it goes in between 2 and 3.
L×w=64 ft^2...(1)
2w+8= l...(2)
l=64-w...(1a)
2w+8= 64-w
2w+w+8=64
3w=64-8
3w÷3= 56÷3
w=18.6'
l×w= 64
l×18.6= 64
l= 64÷18.6
l= 3.44 to the nearest hundredths.
$88.76 - $6.34 - $35.70 -$18.77 = $27.95