Answer:
Step-by-step explanation:
The complete exercise is: "The circumference of a circle is 47.1 and the diameter of the circle is 15. Which best represents the value of π? "
In order to solve this exercise, it is important to remember that the circle can be calculated with the following formulas:
1.
Where "C" is the circumference of the circle and "D" is the diameter of the circle.
2.
Where "C" is the circumference of the circle and "r" is the radius of the circle (Remeber that the diameter is twice the radius).
In this case, the exercise gives you the circumference of the circle and its diameter. These are:
Then, knowing those values, you can substitute them s into the first equation , as following:
The final step is to solve for :
Remark
What this is telling you to do is put 3x + 3 in the question wherever there was an x to start with.
Solution
f(x) = -3x + 4
f(3x + 3) = - 3(3x + 3) + 4
f(3x + 3) = -3*3x + (-3)*(3) + 4
f(3x + 3) = - 9x - 9 + 4
f(3x + 3) = -9x - 5 <<<<< Answer
Choice A is one of the answers. Nice work. This is because x+x+x turns into 3x.
Choice D is the other answer because 2(x+1) + x = 2x+2+x = 3x+2. You can find this through trial and error. Or you could graph y = x+x+x+2 and y = 2(x+1)+2 to find that they are the same exact identical diagonal line. A non-graph approach would be to set up a table of values to see that the two tables are identical.
First, factor out a 3.
3(x² - 9)
In any quadratic ax² + bx + c, we can split the bx term up into two new terms which we want to equal the product of a and c.
In this case, we have x² + 0x - 9. (the 0x is a placeholder)
We want two numbers that add to 0 and multiply to get -9.
Obviously, these numbers are 3 and -3.
Now we have 3(x² + 3x - 3x - 9).
Let's factor.
3(x(x+3)-3(x+3))
<u>3(x-3)(x+3)</u>
There are multiple shortcuts which you could make here, FYI:
Instead of splitting the middle, if your a value is 1, you can go straight to that step (x+number)(x+other number).
Whenever you have a difference of squares, like a²-b², that factors to (a+b)(a-b).
First draw F between E and G in a line.
FG = EG - EF
FG = 4x - 3 - x - 7
FG = 3x - 4