Question 564756
<pre>

<font size=5 color="indigo"><b>The camera has 10.1 million pixels.</font></b> 

let x = the number of pixels across the screen.
let y = the number of pixels up the screen.

<font size=5 color="indigo">The product of the pixels across the screen times the pixels up the screen 
gives the number of pixels the camera has.</font></b>

So 
{{{x*y=matrix(1,2,10.1,million)}}}
{{{x*y=10100000}}}

<font size=5 color="indigo">The ratio of pixels across the screen to pixels up the screen is 4 : 3.</font></b> 
{{{x/y = 4/3}}}

So we have the system of equations:

{{{system(x*y=10100000, x/y=4/3)}}}

<font size=5 color="indigo">How many pixels does this camera have across the screen?</font></b> 

Go to https://www.wolframalpha.com/

Type this in: 

x*y=10100000, x/y=4/3

Press ENTER

Read

{{{matrix(2,2,x = -200 sqrt(1010/3), y = -50 sqrt(3030),
x = 200sqrt(1010/3), y = 50sqrt(3030))}}}

But we know that the answers must be positive, so the answers for x and y are:

{{{matrix(1,2,
x = 200sqrt(1010/3), y = 50sqrt(3030))}}}

If you click on "Approximate forms" you see:

{{{matrix(2,2,x = -3669.7, y = -2752.27,
x = 3669.7, y = 2752.27)}}}

So the value of x is 3669, since the largest whole number that does not 
exceed 3669.7 is 3669. Ikleyn rounded up to 3670 but she should have 
rounded down to 3669.

Answer: 3669 pixels across the screen.

Edwin</pre>