Question 940512
{{{x}}}= Jiri's age,
so {{{x+9}}}= Pamela's age.
The sum of their ages is 89 means
{{{x+(x+9)=89}}}
{{{x+x+9=89}}}
{{{2x+9=89}}}
{{{2x=89-9}}}
{{{2x=80}}}
{{{x=80/2}}}
{{{highlight(x=40)}}}
Jiri's age is {{{highlight(40)}}} .