Question 804072
girls=x boys=y
{{{x+y=330}}}
{{{x=60+y}}}
also written as
{{{x-60=y}}}
plug y=x-60 into x+y=330.
{{{x+x-60=330}}}
{{{2x-60=330}}}
{{{2x=390}}}
{{{x=195}}}
there are 195 girls