23 - x/4 = 13. We need to solve for x.
First, let's work on 23 - x/4. As you can see, we got a subtraction with a fraction. And to be able to add or subtract fractions, both numbers need to have the same denominator. As you know, 23 = 23/1 as a fraction. To transform it to a fraction with a denominator 4, you should multiply the numerator and denominator by 4 (You can NEVER multiply or divide the denominator or numerator alone).
So 23/1 = 92/4.
We got now the equation:
92/4 - x/4 = 13.
Since 92/4 and x/4 have the same denominator, we can regroup them under one denominator:
(92 - x)/4 = 13
Now to get ride of fraction, you multiply by the denominator. So you multiply both sides by 4:
(92-x)/4 * 4 = 13 * 4
92 - x = 52
Now you subtract 92 from both sides to get the variable x alone on a side, and its value on the other side:
92 - x - 92 = 52 - 92
-x = -40
Well, here we got the value of -x. To get the value of x, multiply both sides by -1 (Multiplying 2 negative numbers gives a positive result)
-x * -1 = -40 * -1
x = 40.
So when 23 - x/4 = 13, x=40.
You can recheck your answer (very important):
23 - x/4 = 23 - 40/4 = 23 - 10 = 13.
The answer has been approved.
Hope this Helps! :)