First, see how much money you have:
10 + 3(5) + 8(1) + 12(0.25) + 5(0.1) + 10(0.05) =
10 + 15 + 8 + 3 + 0.5 + 0.5 =
37
You need to deposit $7 into the safe, since 37 - 7 = 30.
I don't know what you mean by monarchy, but monomial in math has 3 terms.
It will take Lauren 1.25 seconds to hit the water.
With the given information, we can write the following quadratic equation.

Now, just use the quadratic formula to solve the equation.
You will get 1.25 and -0.75 as the zeros of the equation (where Laruen hits the water).
Only 1.25 makes sense in the context of this problem.
We analyze the linear function to find that it has equation

. Drawing the line, we find that it
will intersect the circle at negative and positive x-coordinates.We can prove this by
substituting 
into the given equation:




Hence,

or

, so there are both positive and negative values for

.