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.
4t=r
a=pir^2
sub 4t for r
a=pi(4t)^2
a=pi16t^2
a(t)=16pi(t^2)
A. a(t)=16pi(t^2)
B. sub 4 for t
a(4)=16pi4^2
a(4)=16pi16
a(4)=16*16*3.14
a(4)=803.84 square units
A. a(t)=16pi(t^2)
B. 803.84 square units
6 goes into 516 86times.You only divide 516/6
Answer:
12
Step-by-step explanation:
The smaller triangle seems to have dilated and formed the larger triangle. So, let's find the factor of increase.
9 / 3 = 3, so 3 is the factor of increase.
Now we need to do 4 x 3 = 12
So, ? = 12
<em>Hope that helps!</em>
<em>-Sabrina</em>
3 1/4-11/3
31/4 simplifies to 13/4
So you now have 13/4-11/3
Which is -5/12
your final answer is -5/12
