Answer:
-5x^2 +x
Step-by-step explanation:
x(x-2)-3x(2x-1)
Distribute
x^2 -2x -6x^2 +3x
Combine like terms
-5x^2 +x
Answer:
Steps in provided image.
Step-by-step explanation:
<u>Answer:</u>
29 years
<u>Step-by-step explanation:</u>
- Given the function
, where x stands for the number of years since the material was put into the vault, we can plug 140 into x to find the amount leftover. - Another way of doing this is to change the function to
which are equivalent functions, and then plug 140 into x. This function is helpful if you also needed to find the rate. - I'll use the 1st function because the question doesn't ask for the rate

From here I'll just use a calculator & get 28.7, or 29 years.
The surface is parameterized by

and the normal to the surface is given by the cross product of the partial derivatives of
:

It looks like you're given

Then the normal vector is

Now, the point (2, 2, 0) corresponds to u and v such that

and solving gives
, so the normal vector at the point we care about is

Then the equation of the tangent plane is


