I guess that we want to know when both sandcastles will have the same height. We will see that the castles will have the same height after 8 minutes.
We know that Macie sandcastle height is equal to 220cm and wind blows away sand at a rate of 4.8cm per minute, then the height equation is:
M(t) = 220cm - 4.8cm*t
Where t is time in minutes.
While Seth's sandcastle has an initial height of 132cm and its height increases at a rate of 6.2 cm per minute, then the equation is:
S(t) = 132cm + 6.2cm*t
The castles will have the same height when:
M(t) = S(t)
220cm - 4.8cm*t = 132cm + 6.2cm*t
220cm - 132cm = 6.2cm*t + 4.8cm*t
88cm = 11cm*t
88cm/11cm = t = 8
This means that the castles will have the same height after 8 minutes.
If you want to learn more, you can read:
https://brainly.com/question/15253236