Answer:
a₂₁ = 638
Step-by-step explanation:
substitute n = 21 into the explicit formula
a₂₁ = - 2 + 32(21 - 1) = - 2 + 32(20) = - 2 + 640 = 638
Rationalizing the denominator, simply means "getting rid of that pesky root at the bottom", and we do so by simply multiplying it by something to take it out, of course, we multiply the bottom, we have to also multiply the top,
This is 1.446 * 10^9 / 6.025 * 10^4 = 0.24 * 10^5 = 2.4 * 10^4 Answer
the answer is -3/2 and -11/2
#5) 7.065 sq. ft.
#6) 36 ft
#7) 200.96 sq. ft.
#8) 176.625 sq. ft.
Explanation
#5) Converting 18 inches to feet, 18/12 = 1.5. The area of the circle would be given by A=3.14(1.5)² = 3.14(2.25) = 7.065 sq. ft.
#6) The radius is 18 inches, so the diameter is twice that: 18*2 = 36 inches. Converting this to feet, we have 36/12 = 3 feet. Each stone is 3 feet across. Laying 12 of them against each other would give us a total length of 12*3 = 36 feet.
#7) The radius of the entire mirror with frame is 20/2 = 10. The area of the entire mirror with frame is A=3.14(10²) = 3.14(100) = 314 in².
The area of the mirror without the frame is A=3.14(6²) = 3.14(36) = 113.04 in².
The difference between the two will give the area of the frame:
314-113.04 = 200.96 in²
#8) The area of the circular region is given by A=3.14(7.5²) = 176.625 ft²
