B and C I believe .............
Answer:
see the procedure
Step-by-step explanation:
Identify
Let
x ---> the cost of the Xbox one at Walmart
Strategy
we know that
The cost of the Xbox one at Walmart multiplied by 2 plus $50 must be equal to $450
Set up
The algebraic expression that represent this situation is

Solve
solve for x


Check
substitute the value of x in the equation

----> is ok
We are given ratio 456:8.
The given ratio can be written in fraction form as 
In order to find the rate, we need to divide 456 by 8, because it would give the unit value.
When we divide 456 by 8, we first take multiple of 8 closer to the number 45.
8*6=48 but it's greater than 45, so we would take 8*5 =40.
Subtracting 40 from 45, we get 5.
Getting 6 down, we get 56. Take multiple of 8 upto 56.
8*7= 56.
56 -56=0.
So, on dividing 456 by 8 we got 57.
Therefore, rate is 57 per unit.