Answer: a>-13
Step-by-step explanation:
Question:
Solution:
Let the following equation:
![\sqrt[]{12-x}=\text{ x}](https://tex.z-dn.net/?f=%5Csqrt%5B%5D%7B12-x%7D%3D%5Ctext%7B%20x%7D)
this is equivalent to:
![(\sqrt[]{12-x})^2=x^2](https://tex.z-dn.net/?f=%28%5Csqrt%5B%5D%7B12-x%7D%29%5E2%3Dx%5E2)
this is equivalent to:

this is equivalent to:

thus, we can conclude that
x= 3.
Well first you have to add common like terms in this case 2r and -6r to get -4r now your equation is -4r+8=40, now subtract 8 from both sides to leave r by itself and get -4r=32, now divide both sides by -4 to get r=-8
Hope this helps
It should be 11. hope this helps :)