Question 342973
First, find a common denominator, {{{2*9=18}}}
{{{-(4/9)+1/2=-(4/9)(2/2)+(1/2)(9/9)}}}
{{{-(4/9)+1/2=-(8/18)+(9/18)}}}
{{{-(4/9)+1/2=(-8+9)/18)}}}
{{{-(4/9)+1/2=highlight(1/18)}}}