Total is 61.36 not sure how much she should leave for tip
Answer:
C
Step-by-step explanation:
An approximation of an integral is given by:

First, find Δx. Our a = 2 and b = 8:

The left endpoint is modeled with:

And the right endpoint is modeled with:

Since we are using a Left Riemann Sum, we will use the first equation.
Our function is:

Therefore:

By substitution:

Putting it all together:

Thus, our answer is C.
*Note: Not sure why they placed the exponent outside the cosine. Perhaps it was a typo. But C will most likely be the correct answer regardless.
<span>6x^2y + 8x^2 − 30y − 40
= 2x^2(3y + 4) - 10(3y + 4)
= (2x^2 - 10)(3y + 4)
= 2(x^2 - 5)(3y + 4)</span>