Question 548925
There are different ways of writing the same number that are equivalent.
For example {{{3/4=6/8}}}
There are different ways to write the same expression that are equivalent.
When the coefficient of a variable is 1 or -1, it does not need to be written out.
So, {{{1*x=x}}} and {{{-1*x=-x}}}
Just as {{{(-1/5)*3=-(1/5)*3=-1*3/5=-3/5=(-3)/5=(-1*3)/5}}},
if you wrote x instead of 3, {{{(-1/5)*x=-(1/5)*x=-1*x/5=-x/5=(-x)/5=(-1*x)/5}}}
The x is really multiplied times -1/5. By writing it on top of the fraction bar, they are saving ink by avoiding to write the 1.
When you write as -5/6y, you mean -{{{5/6}}}{{{y}}}={{{-(5/6)*y=-5*y/6=-5y/6}}}
To solve {{{-x/5=1/16}}} or {{{(-x)/5=1/16}}} (they are really the same equation),
you can multiply both sides of the equation times {{{(-5)}}}, knowing that the resulting equation will have exactly the same solutions. So, you get
{{{(-x/5)(-5)=(1/16)(-5)}}}
and that simplifies to
{{{(x/5)(5)=-(1/16)(5)}}} --> {{{(x*5)/5=-(1*5)/16}}} --> {{{(x*cross(5))/cross(5)=-5/16}}} --> {{{x=-5/16}}}