The variables are: time(the independent variable or (x) variable) and number of handbags (the dependent variable or (y) variable). The variables helps to plot an accurate points on the graph.
We must graph y=x^3-9x^2+11x+21. Please, see the attached file.
Then we see were the graph cuts the x-axis, and these values of x are the real solutions of the given equation:
The real solutions of the given equation are:x = -1, 3, and 7
1 billion dollars × 6 inches per dollar = 6 billion inches / 63,360 inches per mile = 94,636.97 miles coverted by1 billion bills. answer = 94,636.97 miles
For this case we propose a system of equations:
x: Let the variable representing the quantity of Granny Smith apples
y: Let the variable representing the number of Gala apples
According to the statement we have:

From the first equation we have to:

replacing in the second equation:

So, Carl bought 7 Gala apples
On the other hand:

So, Carl bought 12 Granny Smith apples
Answer:
Carl bought 7 Gala apples and 12 Granny Smith apples
If you divide 40 and 5 it equals $8 for 1 student ticket