This is what we have:
[tex] \frac{x}{5} =a[/tex]
what we want is for x to "stand alone": for this, we need to get rid of this 5. we can do this by multiplying both sides of the equation by 5:
[tex] \frac{x*5}{5} =a*5[/tex]
if we both divide and mupliply the first numebr by 5, it just means 1, so we can skip it:
[tex] x =5a[/tex]
