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).
Answer:
30 degrees
Step-by-step explanation:
If you were to draw a number line, 15 and -15 are both 15 units away from 0. So, 15 + 15 =30
Please brainlist!
Answer:
C
Step-by-step explanation:
A positive charged ion or cation would have more protons than electrons.
Answer:
Step-by-step explanation:
A straight line adds up to 180 degrees, therefore 3x+6x = 180
9x = 180
x = 20
<h3><u>
The value of the number is equal to 16.</u></h3>
7x + 8 = 120
<em><u>Subtract 8 from both sides.</u></em>
7x = 112
<em><u>Divide both sides by 7.</u></em>
x = 16
