Step-by-step explanation:
perimeter formula is adding up all the sides
so
5x-40 + 5x-40 + 3x-18 + 3x -18
= 16x -116
Y = 3x^2 - 3x - 6 {the x^2 (x squared) makes it a quadratic formula, and I'm assuming this is what you meant...}
This is derived from:
y = ax^2 + bx + c
So, by using the 'sum and product' rule:
a × c = 3 × (-6) = -18
b = -3
Now, we find the 'sum' and the 'product' of these two numbers, where b is the 'sum' and a × c is the 'product':
The two numbers are: -6 and 3
Proof:
-6 × 3 = -18 {product}
-6 + 3 = -3 {sum}
Now, since a > 1, we divide a from the results
-6/a = -6/3 = -2
3/a = 3/3 = 1
We then implement these numbers into our equation:
(x - 2) × (x + 1) = 0 {derived from 3x^2 - 3x - 6 = 0}
To find x, we make x the subject of 0:
x - 2 = 0
OR
x + 1 = 0
Therefore:
x = 2
OR
x = -1
So the x-intercepts of the quadratic formula (or solutions to equation 3x^2 - 3x -6 = 0, to put it into your words) are 2 and -1.
We can check this by substituting the values for x:
Let's start with x = 2:
y = 3(2)^2 - 3(2) - 6
= 3(4) - 6 - 6
= 12 - 6 - 6
= 0 {so when x = 2, y = 0, which is correct}
For when x = -1:
y = 3(-1)^2 - 3(-1) - 6
= 3(1) + 3 - 6
= 3 + 3 - 6
= 0 {so when x = -1, y = 0, which is correct}
1. -4a-6=-12
add 6 to both sides
-4a-6+6=-12+6
-4a=-6
Divide by -4

2.

add

to both sides but you will need to make a common denominator on the right


Divide by

which means multiply by the <span>reciprocal</span>.


3.

Distribute

Subtract

Divide

4. 3w+7=20
Subtract
3w=13
Divide

5. -.2p+.4=-1.2
Subtract
-.2p=-1.6
Divide
p=8
6.

Add, made sure you change to common denominator first

Multiply by 4
y=5
Hope that helps
Answer:
It includes it because with out it there will be no center and it wouldn't be right. And with out it ever equation wont be proportional
Step-by-step explanation:
I really hope this helps Im just saying what I think is the answer it is my fault if you get the answer wrong <3
<u>5y</u> = <u>20x - 30</u>
5 5
y = 4x - 6
5(4x - 6) = 20x - 30
5(4x) - 5(6) = 20x - 30
20x - 30 = 20x - 30
<u> +30 +30 </u>
<u>20x</u> = <u>20x</u>
20 20
x = 1
5y = 20(1) - 30
5y = 20 - 30
<u>5y</u> = -<u>10</u>
5 5
y = -2
5(-2) = 20(1) - 30
-10 = 20 - 30
-10 = -10
(x, y) = (1, -2)