Answer:
8+12=20
Step-by-step explanation:
Is there another part to the question or something let me know.
A) The first step needs 100 bricks, the second needs 98, the third needs 96, and so on. Therefore the number of bricks for the nth step is: a_n = a_1 + d(n-1), where a_1 = 100 (the first term), d = -2 (difference).
a_n = 100 - 2(n-1) = 102 - 2n, and for the 30th step, a_30 = 102 - 2*30 = 42. So the top step will need 42 bricks.
b) The total staircase will need: 100 + 98 + 96 + ... + 44 + 42, and there are n = 30 terms. Using the formula for the sum of an arithmetic sequence:
S = (a_1 + a_n)*n/2 = (100 + 42)*30/2 = 2130
Therefore, 2130 bricks are required to build the entire staircase.
I’m gonna bet on D. Since I answered your question. Break my ankles✨
Answer:
How much soil for a raised bed?
Answer: The cost to fill a raised bed with bagged fertile soil (planting mix) adds up quickly. The volume of soil you need is 12 feet times 4 feet times 1.5 feet (length times width times depth equals volume), which comes to 72 cubic feet
Step-by-step explanation: