The vertex would be the point on the right angle like the tip of the right angle
The Business bought a total of 2048 pens.
Easiest way to solve this is to add the amount of bags the business bought.
7 + 9 = 16
After you find to total amount of bags bought you multiply the amount of pens in each bag by the total amount of bags the business bought.
16 * 128 = 2048
The value of 
<u>Solution:</u>
Given: 
To find: The value of (h*h)(10)
We know that, 
which is,

On solving we get,

So, for x = 10 it will be,

Hence, the required value is 10.
Product means multiply, so the product of 12 and 8 would be written as 12 x 8
Then you want 6 less than that so you need to subtract 6
The equation should look like (12 x 8) - 6