Answer:
6:12
Step-by-step explanation:
Add 1+2=3
18/3=6
6x1=6
6x2=12
Out it back in the ratio
6:12
Answer:
34
Step-by-step explanation:
2210 / 65 = 34. There is no further explanation
Answer:
c
Step-by-step explanation:
sorry if wrong
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:

Step By Step Explanation:
Subtract 2 From Both Sides

Simplify

Subtract 9x From Both Sides

Simplify

Multiply Both Sides By -1 (Reverse Inequality)

Simplify

Divide Both Sides By 2

Simplify

- Mordancy