ANSWER QUICK PLEASE! Which of the following is NOT an expression?
A. 3x + 4 = 7
B. 6 - i/5
C. x + 8
D. 2x - 3

Lin is writing an equation to model the proportional relationship between y, the total cost in dollars of downloading videos from a website, and x, the number of videos downloaded. she knows that the total cost to download 3 videos was $12. her work to find the equation is shown below. joylin’s work step 1 k= 3/12= 0.25 step 2 y= 0.25x where did joylin make her first error?