Rime: A number with exactly two factors; one and itself. What does this mean? This means that for us to call a number prime, only two whole numbers can divide into it without a remainder. Here are a few examples: 2, 3, 5, 7, 11<span>, </span>13<span>, </span>17<span>, </span>19<span>, </span>23<span>, and so on.</span>
Answer: 
Step-by-step explanation:
1. You must apply the following formula for calculate the total surface area the regular pyramid:

Where p is the perimeter of the base, l is the slant height and B is the area of the base.
2. The perimeter is, where s is the side length:

3. The faces are isosceles traingles. So, to find the slant height you can divide one base into two equal right triangles and calculate the slant height with Pythagorean Theorem:

4. The base is equal to any face, then both have equal areas. As previously you divide one base into two equal righ triangle to find the slant height, you can calcualte the area of one right triangle and multply it by 2 to calculate B:

Finally substitute values:

Answer:
21-14a
Step-by-step explanation:
You have to distribute the (2/3) into the (15-21a) then add it to the 11. So after distributing the (2/3) into the (15-21a) is (10-14a). Then add that to the 11
Answer: you sold 10 adult tickets and 11 children tickets.
Step-by-step explanation:
Let x represent the number of adult tickets that you sold.
Let y represent the number of children tickets that you sold.
You sold a total of 21 tickets. This means that
x + y = 21
Admission prices are six dollars for adults and four dollars for children. You sell tickets for admission to your school play and collect a total of $104. This means that
6x + 4y = 104 - - - - - - - - - -1
Substituting x = 21 - y into equation 1, it becomes
6(21 - y) + 4y = 104
126 - 6y + 4y = 104
- 6y + 4y = 104 - 126
- 2y = - 22
y = - 22/ -2 = 11
Substituting y = 11 into x = 21 - y, it becomes
x = 21 - 11 = 10
The length would be 90 cm. For every 1 cm of actual size it will be increased by 9. So.....10 x 9 = 90 cm.