Question 1122263

Found this on an SAT Practice test.

(6x-1)/(x+4)

Which of the following is equivalent to the expression above?

A) 6-[25/(x+4)]
B) 6-[1/(x+4)]
C) 6-(1/4)
D) (6-1)/4

Hopefully the parentheses I added make it less confusing.

So, I know it's not C or D, since, well, where did the x go? So, that leaves A and B. I looked at the answers and found that it is A, but why? How can I get from (6x-1)/(x+4) to 6-[25/(x+4)]? Please show steps, I need to learn this so I can get this right in the future.
<pre>
     <u>  6      </u>   
x + 4)6x -  1
      <u>6x + 24</u>
         - 25 <b>(Remainder)</b>

From above, you can see that the answer is: {{{highlight_green(matrix(1,3, 6 - 25/(x + 4), "(CHOICE", "A)"))}}}</pre>