Answer:
The third score must be larger than or equal to 72, and smaller than or equal 87
Step-by-step explanation:
Let's name "x" the third quiz score for which we need to find the values to get the desired average.
Recalling that average grade for three quizzes is the addition of the values on each, divided by the number of quizzes (3), we have the following expression for the average:

SInce we want this average to be in between 80 and 85, we write the following double inequality using the symbols that include equal sign since we are requested the average to be between 80 and 85 inclusive:

Now we can proceed to solve for the unknown "x" treating each inaquality at a time:

This inequality tells us that the score in the third quiz must be larger than or equal to 72.
Now we study the second inequality to find the other restriction on "x":

This ine
quality tells us that the score in the third test must be smaller than or equal to 87 to reach the goal.
Therefore to obtained the requested condition for the average, the third score must be larger than or equal to 72, and smaller than or equal 87:
I haven't done this in a while, but I'm pretty sure the answer is D, (-3, -1.)
If you were to substitute x for -3 and y for -1 in the first inequalities and simplify, it would look like this:
-1 > -3-2
-1 > - 5
And that inequality is true, because -1 is bigger than -5. Let's also substitute in the other inequality, which would be:
-1 > 2(-3) + 2
-1 > -6 + 2
-1 > -4
And -1 is bigger than -4. So, I think the answer would be D because substituting for those values of x and y would stil. make the inequalities true.
Answer:
Y must be negative
Step-by-step explanation:
Use this equation as an example: 5 + -7 = negative
If you add both of them you end up with -2
-2 is a negative integer
Answer: By adding, subtracting, multiplying or dividing both sides until you are left with the variable on its own. Don't multiply or divide by a variable unless you know it is always positive or always negative.
Step-by-step explanation:
Answer: x - int : (3,0)
Step-by-step explanation:
point-slope form: y - y1 = m(x - x1)
m = y2-y1/x2-x1
= -4-2/-3-6
=-6/-9
= 2/3
y1 = 2
x1 =6
y - 2 = 2/3(x-6)
x -int: when y = 0, what is x?
0-2 = 2/3(x-6)
-2 = 2/3x - 4
2 = 2/3x
x=3
~Hope this helps!~