Answer:
-7
Step-by-step explanation:
Step-by-step explanation:
Use the vertex
![- 8 {x}^{2} + 6](https://tex.z-dn.net/?f=%20-%208%20%7Bx%7D%5E%7B2%7D%20%20%2B%206)
formula, we know that h is 0 and k is 6 so we get
![a(x {}^{2} ) + 6](https://tex.z-dn.net/?f=a%28x%20%7B%7D%5E%7B2%7D%20%29%20%2B%206)
Now, we set that equal to y and plug in -1 for x and -2 for y to solve for a.
![a( (- 1) {}^{2} ) + 6 = - 2](https://tex.z-dn.net/?f=a%28%20%28-%201%29%20%7B%7D%5E%7B2%7D%20%29%20%2B%206%20%3D%20%20-%202)
![a(1) + 6 = - 2](https://tex.z-dn.net/?f=a%281%29%20%2B%206%20%3D%20%20-%202)
![a = - 8](https://tex.z-dn.net/?f=a%20%3D%20%20-%208)
So our formula is
![- 8( {x}^{2} ) + 6](https://tex.z-dn.net/?f=%20-%208%28%20%7Bx%7D%5E%7B2%7D%20%29%20%2B%206)
ir
![- 8 {x}^{2} + 6](https://tex.z-dn.net/?f=%20-%208%20%7Bx%7D%5E%7B2%7D%20%20%2B%206)
Answer: x = 20
Step-by-step explanation:
1) Move all terms to the left:
x-13-(x/2-3)=0
2) Get rid of parentheses
x-x/2+3-13=0
3) Multiply all the terms by the denominator
x*2-x+3*2-13*2=0
4) Add all the numbers together, and all the variables
-1x+x*2-20=0
5) Multiply elements
-1x+2x-20=0
6) Add all the numbers together, and all the variables
x-20=0
7) Move all terms containing x to the left, all other terms to the right
x=20
Hope This Helps (From My Notes)