Answer:
13a
Step-by-step explanation:
9a + 3a + a = 13a
Suppose that the number u were thinking about is x thus :
![\frac{1}{4} x + \frac{1}{2} x = 12 \\](https://tex.z-dn.net/?f=%20%5Cfrac%7B1%7D%7B4%7D%20x%20%2B%20%20%5Cfrac%7B1%7D%7B2%7D%20x%20%3D%2012%20%5C%5C%20)
Multiply both sides by 4
![4 \times ( \frac{1}{4} x + \frac{1}{2} x) = 4 \times 12 \\](https://tex.z-dn.net/?f=4%20%5Ctimes%20%28%20%5Cfrac%7B1%7D%7B4%7D%20x%20%2B%20%20%5Cfrac%7B1%7D%7B2%7D%20x%29%20%3D%204%20%5Ctimes%2012%20%5C%5C%20)
![x + 2x = 48](https://tex.z-dn.net/?f=x%20%2B%202x%20%3D%2048)
![3x = 48](https://tex.z-dn.net/?f=3x%20%3D%2048)
Divide both sides by 3
![\frac{3x}{3} = \frac{48}{3 } \\](https://tex.z-dn.net/?f=%20%5Cfrac%7B3x%7D%7B3%7D%20%20%3D%20%20%5Cfrac%7B48%7D%7B3%20%20%7D%20%20%5C%5C%20)
![x = 16](https://tex.z-dn.net/?f=x%20%3D%2016)
It means it is "an element of"
Answer:
Step-by-step explanation:
3/4a>-16=
a >- 64/3 or -21 1/3