Answer:
The answer is 21 minutes
Step-by-step explanation:
We use the equation Xf = Xo + vt
1) At 1:00 PM, child one leaves the starting point heading north at a constant velocity of 6 mi/hr or .1 [mi/min] (divide by 60 to convert from [mi/hr] to [mi/min])
2) He walks for 15 minutes before kid 2 starts walking. In 15 minutes he is able to cover 1.5 [mi]
3) Now, child 2 starts walking and we know that when the range reaches 3 miles, they won´t be able to communicate. So the sum of the final position of child 1 and child 2 must be 3[mi]
- Child 1 final position =>

- Child 2 final position =>

4) Sum the equations and equate to 3
5) Substitute the values we already know
6) in 15 + 6 minutes they will be 3miles apart
7) In 21 minutes they will still be able to communicate with one another.
You start by distributing: 8s-4=7s+12
Combine like terms: 8s-7s=12+4
Solve and get your answer: s=16
Answer:
5
Step-by-step explanation:
Square Root - Finding a number that multiplies itself twice into the number within the square root
With this meaning, we need to find a number that multiplies itself into 625.
Finding calculations using exponents will help,
25^2 is equal to 625. Therefore 
We are not finished, as there is another square root right after, empowering the parenthesis, so what number multiplies itself equals 25?
This would be 5, therefore
is equal to 5.
Answer:
$968
Step-by-step explanation:
x= the money John originally had in his savings account
The statement says that John spent $88 on a radio and 1/4 of what was left on presents for his friends. This means that the remaining money is 3/4 of the total amount minus the money spent on the radio:
3/4(x-88)
Then, it says that of the money remaining, John put 4/11 into a checking account and the last remaining $420 was left to charity. Since, he spent 4/11 of the remining 3/4(x-88), the remaining is 7/11 of that and that remaining is equal to $420 that was the money left at the end:
7/11(3/4(x-88))= 420
21/44(x-88)=420
21/44x-42=420
21/44x=462
x=968
According to this, the money that John originally had in his savings account was $968.
He spent $88 on a radio: 968-88= 880
1/4 of what was left on presents for his friends: 880/4= 220
880-220=660
Of the money remaining, John put 4/11 into a checking account: 660*(4/11)=240
the last remaining $420 was left to charity: 660-240= 420
20% of 1000 = 200
40% of 200 = 80
Therefore there are 80 red sneakers
Hope this helps :)