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.
the angles the top part that has a square is 90⁰ and x and y are equal so we will name them both x and all angles together make 180⁰
I don't know about the sides
Step-by-step explanation:
90+x+x=180
2x=180-90
2x=90
x=90/2
x=45
Add 2 to 3 and then your answer is x>5
V= m/d. When you get questions asking about density/mass/volume draw a triangle just like in the picture i have attached and with your finger cover up the one you are looking for. So to find the equation for volume you cover up volume and you are left with mass divided by density.
