The equations y = 30x + 10 and y = –x2 + 150x + 10 model the daily sales of two car models, where x represents the number of days since the cars went on sale. On what day was the same number of each car sold?

  day 0, day 120

Step-by-step explanation:

You want to find the value of x that makes both y-values be the same:

  y = y

  30x +10 = -x^2 +150x +10

  x^2-120x = 0 . . . . subtract the right side of the equation

  x(x -120) = 0 . . . . . factor

Values of x that make this true are x=0 and x=120.

The same number of each car was sold on day 0 and day 120.

n

step-by-step explanation:

to plot points   for x just start at the origin (middle) and go to the left however many times it say(if the number is a positive) if the number is a negative then go right however many times it says if it is 0 go nowhere

now keep you pencil there and go up however many times it says on y(if it is positive) if it is negative then go down however many times it says. if it says 0 go nowhere.

you have just plotted a point! now when you finish plotting all of them connect them with a ruler

plot each point as (-3, 7), (0,4), (3,1), (8,-4)   in the parenthesis on the left of the comma is x and the right is y.