It works because 7 x 9 x 10 is the same thing as 7 x 90, since 9 x 10 is just 90. So basically he is just writing more but the answer will still be the same.
Answer:
B
Step-by-step explanation:
Since the triangle is right use the tangent ratio to find x
tan64° =
=
Multiply both sides by 11
x = 11 × tan64° = 22.55 → B
Answer:

Step-by-step explanation:
Given



Required
The volume of the remaining cylinder
Before the cut-out, the cylinder has a volume (V) of:

After the cut-out, the cylinder has a volume of:
![V = \pi [R^2 -r^2]h](https://tex.z-dn.net/?f=V%20%3D%20%5Cpi%20%5BR%5E2%20-r%5E2%5Dh)
So, we have:
![V = 3.14* [6^2 -5^2]*15](https://tex.z-dn.net/?f=V%20%3D%203.14%2A%20%5B6%5E2%20-5%5E2%5D%2A15)
![V = 3.14* [36 -25]*15](https://tex.z-dn.net/?f=V%20%3D%203.14%2A%20%5B36%20-25%5D%2A15)


2x + 5 > 3x + 1
<u> - 2x - 2x </u>
5 > x + 1
<u>- 1 - 1</u>
4 > x
x < 4
Ok, listen up
This sign -> "<" means less than
Therefore, the expression is 5 < 8