<u>0.09</u> = <u>1 </u>
0.9 10
I hope this helps.
Each of them need to work 105 minutes more in order to have packed the same number of boxes.
<u><em>Explanation</em></u>
Suppose, they need to work for 
minutes more in order to have packed the same number of boxes.
Selma packs one box in 5 minutes and Trudy packs one box in 7 minutes.
So, the number of boxes packed by Selma in that minutes 
and the number of boxes packed by Trudy in minutes 
Given that, Selma and Trudy have already packed 12 and 18 boxes.
Now if <u>each of them packed the same number of boxes</u>, then the equation will be......
So, each of them need to work 105 minutes more in order to have packed the same number of boxes.
What type of model are you talking about?
Because of the symmetry, we can just go from x=0 to x=2 to find the area between
<span>y = x^2 and y = 4 </span>
<span>that area = ∫4-x^2 dx from 0 to 2 </span>
<span>= [4x - (1/3)x^3] from 0 to 2 </span>
<span>= 8 - 8/3 - 0 </span>
<span>= 16/3 </span>
<span>so when y = b </span>
<span>x= √b </span>
<span>and we have the area as </span>
<span>∫(b - x^2) dx from 0 to √b </span>
<span>= [b x - (1/3)x^3] from 0 to √b </span>
<span>= b√b - (1/3)b√b - 0 </span>
<span>(2/3)b√b = 8/3 </span>
<span>b√b =4 </span>
<span>square both sides </span>
<span>b^3 = 16 </span>
<span>b = 16^(1/3) = 2 cuberoot(2) </span>
<span>or appr 2.52</span>
