Answer:
It equals -2
Step-by-step explanation:
Answer:
6
....................................
Distance from home to store = 4 * 0.5 = 2 miles.
Time taken to return home = (2/12) * 60 =10 minutes.
Total distance traveled = 2 * 2 = 4 miles.
Total time taken = 30 + 10 = 40 minutes.
Average speed for entire trip = total distance / total time in hours.
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
We have a system of equations in two variables, namely, a and c. Use the substitution to find a and c.