13. Is 18
15. Is 86
17 is 5
19 is 15
21 is 24
23 is 29
Answer:
C
Step-by-step explanation:
We have:

Where a<0.
We would like to solve for a. So, let’s divide both sides by a.
Notice that a<0. Therefore, a is negative. Hence, we must flip the sign since we are dividing by a negative. This yields:

Now, we will subtract b from both sides. Therefore, our inequality is:

Hence, our answer is C.
Solve first for the solution of the inequalities. This can be done by replacing first the inequalities sign with the equal sign.
x + y = 1
2y = x - 4
The values of x and y from the system of linear equation are 2 and -1. This means that the intersection of the lines should be at point (2, -1).
Substitute 3 to x and determine the value of y from the second inequality.
2y ≥ x - 4
Substituting,
2y ≥ 3 - 4, y ≥ -1/2
Hence, the solution to this item should be the fourth one.
Answer:
A
Step-by-step explanation:
Two facts need to guide your answer.
One
The highest power is odd: you know this because an even power would start on the left come down do it's squiggles if had any and wind up on the right going up.
This graph comes down on the left does it's squiggles and then goes further down on the right. That's the behavior of something whose highest power is odd.
Two
The leading coefficient, the number in front of the highest power must be minus. If it was positive as in y = x^3 the graph would be the mirror image of what it is.
Argument
B and D cannot be true. The highest power is even.
C is false because the leading coefficient is + 1.
So that leave A which is the answer.
The graph is included with this answer
Answer:

Step-by-step explanation:
Alrighty let's do this.
We know that formula for the Area of a triangle is:

They give us the area as
, so let's include it in the equation.

Now we reach a stage where we have 2 unknown variables! That means we can't solve it in its current state. So the idea you should have in cases like these where you have 2 or more unknown variables is, "Can I represent this one variable in terms of another variable?" In this case you can do exactly that. You can represent height in terms of length of the base. We are told the height of the triangle is 4 meters less than the base. That is telling us that 
So replace
in the equation with
.
You will now get:

Now we can work towards solving. Let's get simplifying.

bring everything to one side so we can make a quadratic and factor:

We get that
.
Since we need the height of the triangle we'll need to call back on what h is. We found earlier that
, so to find h, we just sub in our b value into that.

We find that 