Answer:
The answer is D. 65
Explanation:
The first step is to substitute n as 4 and k as 13. This results in the fraction
=
. Since there is an equal sign, this indicates you can cross multiply. That means that you would multiply the 4 with the x and the 20 with the 13. This results in the next step, which is 4x=20(13) ---> 4x=260. Finally, to find the value of x, divide the 4 from the x to isolate it. The reasoning behind this is that you have to do the inverse operation, meaning since 4 is being multiplied by x, the inverse of this is dividing by 4 to get x by itself. Also, whatever you do on one side of the equal sign, you have to do it on the other. Therefore,
; x=65.