Add 2x + 5 and 4x - 7
Then you isolate the variable or “get rid of” the numbers that re stopping you from getting “x”.
By doing the inverse operation.
If you add ___ you subtract ____ it form itself
If you subtract ___ you add ____ To itself.
So you Cancel out by getting rid of the other numbers.
Same thing with multiplying and dividing.
If you multiply ____ you divide___ but don’t divide “x”
Only the integer.
If you divide _____ you multiply ____ it
Answer:
D. Up
Step-by-step explanation:
When a parabola has the form
, It is vertical (opens up or down).
Because the variable "x" is squared.
If "a" is positive, then the parabola opens up, but if it is negative, then the parabola opens down.
In this case you have the quadratic function:

Which can be rewritten as:
Therefore, it is vertical, because it has the form: 
You can observe that the value of "a" is:

Then, since "a" is positive, the parabola opens up.
Answer:
There were 26 students in his class and the teacher had 83 ml of the solution.
Step-by-step explanation:
Mr. Kohl has a "x" amount of solution, if he divides it by the number of students "n" he'll give each student 3 milliliters and have a left over of 5 milliliters. If the amount of solution Mr. Kohl had was "x + 21" then he'd be able to give each student 4 milliliters of the solution. From these informations we have:
x = 3*n + 5
(x + 21)/n = 4
x + 21 = 4*n
x = 4*n - 21
Now that we have two equations and two variables we can solve the system of equations, as seen bellow:
3*n + 5 = 4*n - 21
3*n - 4*n = -21 - 5
-n = -26
n = 26
x = 4*26 - 21 = 83 ml
There were 26 students in his class and the teacher had 83 ml of the solution.