Question 1047603
You can always plug your answer into the original equation to see if it solves it.
{{{4a-(3-a)=17 }}}
{{{4(14)-(3-14)=17}}}
{{{56-(-11)=17}}}
{{{56+11=17}}}
{{{67=17}}}
No, it's not a solution
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 {{{4a-3-a=17 }}} <---- Here is your mistake, when you distribute the (-1)
{{{4a-(3-a)=17}}}
{{{4a-3-(-a)=17}}}
{{{4a-3+a=17}}}
Now continue and finish the solution. 
Then check it in the original equation.