When a line in a slope graph has no rise/run like this one, there is no slope.
The slope is "Undefined".
Finding perimeter is simple. All you do is add up all of the side lengths, and bada bing bada boom, you got the perimeter.
V=L X W X H
1,296=6 x w x 24
1,296=144 x w
1296/144=w
9=width
|4r + 8| ≥ 32
Split this expression into two expressions:
First ⇒ 4r + 8 ≥ 32 and second ⇒ 4r + 8 ≤ - 32
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First expression: 4r + 8 ≥ 32
Subtract 8 from both sides.
4r ≥ 24
Divide both sides by 4.
r ≥ 6
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Second expression: 4r + 8 ≤ - 32
Subtract 8 from both sides.
4r ≤ -40
Divide both sides by 4.
r ≤ -10
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Your answer is 
~Hello There!~

Rearrange for s

After 8 years, the new equation would be:

Cross multiply

Subtract 8

Substitute old equation

Solve to get m as 16.
s = 40.
Their current ages are 16 and 40 and the different is 24 years. Therefore, Caitlin is correct.
Hope This Helps You!
Good Luck :)
Have A Great Day ^_^
- Hannah ❤