Question 112393
No, that's not correct.
Remember the definition of the absolute value function,
{{{abs(x)=x}}} if {{{x>=0}}}
{{{abs(x)=-x}}} if {{{x<0}}}
Let's look at your values separately.
{{{abs(-8)=-(-8)=8}}}
{{{abs(3)=3}}}
{{{abs(-8+3)=abs(-5)=-(-5)=5}}}
If we use you equality, then
{{{abs(-8)+abs(3)=abs(-8+3)}}}
{{{8+3=5}}}
{{{11=5}}}
The absolute value function has the following property, called subadditivity,
{{{abs(x+y)<=abs(x)+abs(y)}}}
and in your case leads to 
{{{abs(-8+3)<=abs(-8)+abs(3)}}}
{{{5<=11}}}
which is a true statement