Answer:
Option D
Step-by-step explanation:
Whenever we take a square root of a number the ± sign is with it like here in the question

And then x = ±4.47 which means x has two values one is +4.47 and the other is -4.47 so Option D is our answer.
Let the cost of the soft drink = C then the price of the sandwich was 3.5 times as much = 3.5C
And
C + 3.5C = Total Cost
C + 3.5C = 9
4.5C = 9 divide both sides by 4.5
C = 9/4.5 = $2.00 for the soft drink
And 3.5C = 3.5(2.00) = $7.00 cost of the sandwich
X is equal to 12
This is because 5 was multiplied and 6 making 30. So you have to multiply 2 and 6 making x 12. Hope that makes sense
For number one the media is 22 and 5
The first pipe fills 1/8 of a pool in one hr.
The second pipe fills 1/4 of a pool in one hr.
(1/8+1/4)2= 3/4 done by the first two pipes in 2 hours.
Therefore the last pipe must do 1 1/4 of the filling in 2 hours, which is 5/8 per hour.
5/8x=1
x=8/5
It takes the third pipe 1 hour and 36 minutes to fill it by itself.