Answer:
9
Step-by-step explanation:
15(8-2)
15-(6)
9
This problem is an example of an arithmetic series.
The common difference of the second term (15) with the first term (9) and the third term (21) with the second term (15) [15-9=6; 21-15=6] is 6.
The formula for solving this is:
An= A1 +(n-1)*d where An is the nth term, A1 is the first term, n is the number of terms and d is the common difference.
An=9+ (31-1)*6 = 189
The answer is 189.
Answer:
2592 cm
Step-by-step explanation:
square area = x²
rectangle area = bh
so
x² = bh
since the areas are equal
b and h are in the problem as 64 and 81
x² = 64x81
x² = 5184
divide by 2
x = 2592 cm
Answer:
1256000
Step-by-step explanation:
My example:
Find the radius of the sphere by substituting 4.5? ft^3 for V in the formula in Step 1 to get: V=4.5? cubic feet.= (4/3)?(r^3)
Multiply each side of the equation by 3 and the equation becomes: 13.5 ? cubic feet =4?(r^3)
Divide both sides of the equation by 4? in Step 4 to solve for the radius of the sphere. To get: (13.5? cubic feet)/(4?) =(4? )(r^3)/ (4?), which then becomes: 3.38 cubic feet= (r^3)
Use the calculator to find the cubic root of 3.38 and subsequently the value of the radius “r” in feet. Find the function key designated for cubic roots, press this key and then enter the value 3.38. You find that the radius is 1.50 ft. You can also use an online calculator for this calculation (see the Resources).
Substitute 1.50 ft. in the formula for SA= 4?(r^2) found in Step 1. To find: SA = 4?(1.50^2) = 4?(1.50X1.50) is equal to 9? square ft.
Substituting the value for pi= ?= 3.14 in the answer 9? square ft., you find that the surface area is 28.26 square ft. To solve these types of problems, you need to know the formulas for both surface area and volume.
X^3 + h^3 - 3x-3h - x^3 +3x h^3 - 3h h^2 - 2h
------------------------------------- = ------------------ =
h h
