Solving equations simple
9n + 12 = 30
Answer:
12 sides
Step-by-step explanation:
To find the number of sides of a regular polygon with the sum of interior angles of 1800 degrees, we will follow the steps below;
first write down the formula for finding sum of the interior angle of a polygon
s= (n-2)180
where s is the sum of the interior angle and n is the number of side
from the question given, sum of the interior angle s=1800 degrees
substitute s=1800 degree into the formula and solve for n
s= (n-2)180
1800 = (n-2)180
divide both-side of the equation by 180
1800/180 = n-2
10 = n - 2
add 2 to both-side of the equation
10 + 2 = n
12 = n
n= 12
The polygon have 12 sides
Use the pythagoream theorem to check. a^2+b^2=c^2
a=15 b=36 c= 39
225+1296=1521
The equation is true so it is a right triangle.
Answer:
a) 35, b) 25, c) 60
Step-by-step explanation:
The number of girls is 10 more than the number of boys, so it's a good thing to choose a variable to represent the number of boys.
Number of boys: b
Number of girls: b + 10
Ratio of girls:boys is 7:5, so

"Cross multiply" to get

There are 25 boys. There are 10 more girls, so the number of girls is 35, and the total number of students is 60.
That's a packed classroom!
Answer: 7 π r² + π r³
Explanation:
1) The general formula for the volumen, V, of a cylinder with radius r and height h is:
V = π r² h
2) Now you have the condition that the height is 7 inches greater than the radius, that is:
h = 7 + r
3) Replace h with its expression
V = π r² (7 + r)
4) Expand the product (use distributive property):
V = π (7r²) + π r³ = 7 π r² + π r³
Answer: 7 π r² + π r³