Given:


To find:
The value of
.
Solution:
We have,
![[\because d(t)=80t]](https://tex.z-dn.net/?f=%5B%5Cbecause%20d%28t%29%3D80t%5D)

Now,
![[\because C(d)=0.09d]](https://tex.z-dn.net/?f=%5B%5Cbecause%20C%28d%29%3D0.09d%5D)

Therefore, the value of
is 72.
Answer:
d=−bc+a/0.5bc
Step-by-step explanation:
Let's solve for d.
a=0.5bcd+bc
Step 1: Flip the equation.
0.5bcd+bc=a
Step 2: Add -bc to both sides.
0.5bcd+bc+−bc=a+−bc
0.5bcd=−bc+a
Step 3: Divide both sides by 0.5bc.
0.5bcd/0.5bc = −bc+a/0.5bc
d=−bc+a/0.5bc
Answer:
There were 210 downloads of the standard version.
Step-by-step explanation:
This question can be solved using a system of equations.
I am going to say that:
x is the number of downloads of the standard version.
y is the number of downloads of the high-quality version.
The size of the standard version is 2.6 megabytes (MB). The size of the high-quality version is 4.2 MB. The total size downloaded for the two versions was 4074 MB.
This means that:

Yesterday, the high-quality version was downloaded four times as often as the standard version.
This means that 
How many downloads of the standard version were there?
This is x.

Since 




There were 210 downloads of the standard version.
Answer:

Step-by-step explanation
The standard equation of a circle centered at origin is 
r = radius of the circle
The circle is passing through the point (0,5)
∴ radius 



∴ The equation of the circle is

What ever solution is left over after solved