Minus the 21 from the other side of the equation making it 7x=-21 then u divide the 7 from the x to the -21 resulting in x=-3
Answer:
4th option
Step-by-step explanation:
7x(8x² - 4y² + 3y - 5) ← multiply each term in the parenthesis by 7x
= 56x³ - 28xy² + 21xy - 35x
(a) First find the intersections of

and

:

So the area of

is given by

If you're not familiar with the error function

, then you will not be able to find an exact answer. Fortunately, I see this is a question on a calculator based exam, so you can use whatever built-in function you have on your calculator to evaluate the integral. You should get something around 0.5141.
(b) Find the intersections of the line

with

.

So the area of

is given by


which is approximately 1.546.
(c) The easiest method for finding the volume of the solid of revolution is via the disk method. Each cross-section of the solid is a circle with radius perpendicular to the x-axis, determined by the vertical distance from the curve

and the line

, or

. The area of any such circle is

times the square of its radius. Since the curve intersects the axis of revolution at

and

, the volume would be given by
<h3>Answer: Choice C</h3>
- domain = (-infinity, infinity)
- range = (-infinity, 0)
- horizontal asymptote is y = 0
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Explanation:
Since no division by zero errors are possible, and other domain restricting events are possible, we can plug in any x value we want. This means the domain is the set of all real numbers. Representing this in interval notation would be (-infinity, infinity).
The range is the set of negative real numbers, which when written in interval notation would be (-infinity, 0). This is because y = 5^x has a range of positive real numbers, and it flips when we negate the 5^x term. The graph of y = -5^x extends forever downward, and the upper limit is y = 0.
It never reaches y = 0 itself, so this is the horizontal asymptote. Think of it like an electric fence you can get closer to but can't touch.