you want me to do step by step or just tell you the answer?
Step-by-step explanation:
Answer:
Step-by-step explanation:
Correct
Answer:
$9$
Step-by-step explanation:
Given: Thea enters a positive integer into her calculator, then squares it, then presses the $\textcolor{blue}{\bf\circledast}$ key, then squares the result, then presses the $\textcolor{blue}{\bf\circledast}$ key again such that the calculator displays final number as $243$.
To find: number that Thea originally entered
Solution:
The final number is $243$.
As previously the $\textcolor{blue}{\bf\circledast}$ key was pressed,
the number before $243$ must be $324$.
As previously the number was squared, so the number before $324$ must be $18$.
As previously the $\textcolor{blue}{\bf\circledast}$ key was pressed,
the number before $18$ must be $81$
As previously the number was squared, so the number before $81$ must be $9$.
If we had AB: BC: CD, we could easily have solved that problem. In order to combine these ratios, we need to have the same number for BC. We can create this number by finding LCM (Least Common Multiple) for 5 and 3, which is 15. Then, we can write ratios of AB:BC = 6:15 and BC:CD=15:20. Now, we can easily combine these ratios. AB:BC:CD = 6:15:20. Then, 6k+15k+20k = 82 and k=2 cm. And BC = 30 cm
