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.
Answer:
scalene right
Step-by-step explanation:
no side congruent and right
We look at the point that has not moved and another point (if neccecary)
the point that has not moved is on the axis of reflection
that pont is D
we see in my diagram that the only axis that that is on is x=0
the answer is B. x=0
4 dirhams is equal to 1 dollar so if you were to multiply each by 5 you would have 20 dirhams equaling 5 dollars
