Answer:
(-∞ , -1) ∪ [ 2 , +∞)
Step-by-step explanation:
The cost for 9 lbs would be 63 dollars
Answer:
7. A = 40.8 deg; B = 60.6 deg; C = 78.6 deg
8. A = 20.7 deg; B = 127.2 deg; C = 32.1 deg
Step-by-step explanation:
Law of Cosines

You know the lengths of the sides, so you know a, b, and c. You can use the law of cosines to find C, the measure of angle C.
Then you can use the law of cosines again for each of the other angles. An easier way to solve for angles A and B is, after solving for C with the law of cosines, solve for either A or B with the law of sines and solve for the last angle by the fact that the sum of the measures of the angles of a triangle is 180 deg.
7.
We use the law of cosines to find C.






Now we use the law of sines to find angle A.
Law of Sines

We know c and C. We can solve for a.


Cross multiply.





To find B, we use
m<A + m<B + m<C = 180
40.8 + m<B + 78.6 = 180
m<B = 60.6 deg
8.
I'll use the law of cosines 3 times here to solve for all the angles.
Law of Cosines



Find angle A:





Find angle B:





Find angle C:





Answer:
The volume = 
Step-by-step explanation:
* The rule of the volume of the rectangular prism:
- the volume of any prism = base area × height
∵ The base of the rectangular prism is rectangle
∵ Area any rectangle = Length × Width = l × w
∴ The volume of the rectangular prism = l × w × h
* In the problem:
∵ l = x , w = x² , h = 5x² + 4x + 1
∴ The volume = (x)(x²)(5x² + 4x + 1)
* We will simplify it
- Multiply x by x² and then multiply the answer by the bracket
∵ x × x² = x³
∴ x³(5x² + 4x + 1)
∵ x³ × 5x² = 5x^5
∵ x³ × 4x = 4x^4
∵ x³ × 1 = x³
∴ The volume = 