A box of chocolates costs $7. Which equation relates the number of boxes sold (x) and total cost of the boxes sold (y)? A. 7x = y B. x = 7 + y C. x = 7y D. x + 7 = y E. x + y = 7

A. 7x=y

Step-by-step explanation:

7$ is the for the box of chocolate.

x is equal to the  ammount sold

therefore you would say 7 times x equals y

in this case 7x=y

let's call the solutions x₁ = (5 - 2√7)/3 and x₂ = (5 + 2√7)/3

then the equation is (x-x₁)(x-x₂) = 0

if you fill that in you get a lot of numbers which you can recognize as ax²+bx+c=0.

step-by-step explanation:

you can see that a=1 (there is just an x²)

b = (-5 -2√7 + 2√7 - 5)/3 = -10/3

c = -2√7)/3 ) * (-5+2√7)/3) = -1/3

so your answer is 3x^2 – 10x – 1 = 0