Answer:
A
Step-by-step explanation:
Antonia: 150 x 12 + 4,500 = 6,300
Cal: 250 x 12 + 3,400 = 6,400
The <em>echo</em> number 20222022202220222022 is the <em>perfect</em> square of 4496890281.
<h3>What echo number is a perfect square</h3>
An <em>echo</em> number has a <em>perfect</em> square if its square root is also a <em>natural</em> number. After some iterations we found that <em>echo</em> number 20222022202220222022 is a <em>perfect</em> square:

The <em>echo</em> number 20222022202220222022 is the <em>perfect</em> square of 4496890281. 
To learn more on natural numbers, we kindly invite to check this verified question: brainly.com/question/17429689
Answer:
-20/3 & -40/3
Step-by-step explanation:
Let’s say that the 1st number is X and the 2nd number is Y.
Given that x:y = 1:2 => x/y = 1/2 => 2x = y
and a-5/y+4 = 5/4 (The first number is decreased by 5 and the second number is increased by 4.)
=> 4(x - 5) = 5 (y + 4)
=> 4x - 20 = 5y + 20
=> 4x - 5y = 40
As, 2x = y , 4x = 2y
=> 2y - 5y = 40
=> -3y = 40
=> y = -40/3 ; x = y/2 = -20/3
This might be confusing but I hope this helps :)
Answer:
89.6
Step-by-step explanation: