Answer:
B 2 2/3
Step-by-step explanation:
Triangles ADB and CDB are similar. Therefore similar parts can form a proportion.
AD/DB = DB/DC
AD = ?
DB = 4
DC = 6
x/4 = 4/6 Cross multiply
6x = 16
6x/6 = 16/6
x = 2 4/6 or x = 2 2/3
It's B
Answer:
![\displaystyle a:b=\frac{1}{3}](https://tex.z-dn.net/?f=%5Cdisplaystyle%20a%3Ab%3D%5Cfrac%7B1%7D%7B3%7D)
Step-by-step explanation:
<u>Ratios
</u>
We are given the following relations:
![a=\sqrt{7}+\sqrt{c}\qquad \qquad[1]](https://tex.z-dn.net/?f=a%3D%5Csqrt%7B7%7D%2B%5Csqrt%7Bc%7D%5Cqquad%20%5Cqquad%5B1%5D)
![b=\sqrt{63}+\sqrt{d}\qquad \qquad[2]](https://tex.z-dn.net/?f=b%3D%5Csqrt%7B63%7D%2B%5Csqrt%7Bd%7D%5Cqquad%20%5Cqquad%5B2%5D)
![\displaystyle \frac{c}{d}=\frac{1}{9} \qquad \qquad [3]](https://tex.z-dn.net/?f=%5Cdisplaystyle%20%5Cfrac%7Bc%7D%7Bd%7D%3D%5Cfrac%7B1%7D%7B9%7D%20%5Cqquad%20%5Cqquad%20%5B3%5D)
From [3]:
![9c=d](https://tex.z-dn.net/?f=9c%3Dd)
Replacing into [2]:
![b=\sqrt{63}+\sqrt{9c}](https://tex.z-dn.net/?f=b%3D%5Csqrt%7B63%7D%2B%5Csqrt%7B9c%7D)
We can express 63=9*7:
![b=\sqrt{9*7}+\sqrt{9c}](https://tex.z-dn.net/?f=b%3D%5Csqrt%7B9%2A7%7D%2B%5Csqrt%7B9c%7D)
Taking the square root of 9:
![b=3\sqrt{7}+3\sqrt{c}](https://tex.z-dn.net/?f=b%3D3%5Csqrt%7B7%7D%2B3%5Csqrt%7Bc%7D)
Factoring:
![b=3(\sqrt{7}+\sqrt{c})](https://tex.z-dn.net/?f=b%3D3%28%5Csqrt%7B7%7D%2B%5Csqrt%7Bc%7D%29)
Find the ration a:b:
![\displaystyle a:b=\frac{\sqrt{7}+\sqrt{c}}{3(\sqrt{7}+\sqrt{c})}](https://tex.z-dn.net/?f=%5Cdisplaystyle%20a%3Ab%3D%5Cfrac%7B%5Csqrt%7B7%7D%2B%5Csqrt%7Bc%7D%7D%7B3%28%5Csqrt%7B7%7D%2B%5Csqrt%7Bc%7D%29%7D)
Simplifying:
![\boxed{a:b=\frac{1}{3}}](https://tex.z-dn.net/?f=%5Cboxed%7Ba%3Ab%3D%5Cfrac%7B1%7D%7B3%7D%7D)
Answer:
4 sales signs
Step-by-step explanation:
7x + 10 = 38
<em>Subtract 10</em>
7x = 28
<em>Divide 4</em>
x = 4
Hello from MrBillDoesMath!
Answer: 6 * 10^(-6)
Discussion:
0.000006 = 6 * ( .000001) = 6 * 10^(-6)
Regards,
MrB