<span>i think the answer is but i am not a 100%
5.41853992195
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The answer is 18cm for the radius
-1.5(4-n)+2.8
multiply 4-n by -1.5
multiply to both the 4 and -n
-6+1.5n+2.8
add -6+2.8 since they are similar
-3.2+1.5n
1.5n-3.2
I believe this is the simplest form
Answer:

Step-by-step explanation:
<em>Look at the picture.</em>
<em />
We have:

Therefore
<em>divide both sides by 2</em>
