Answer:
98
Step-by-step explanation:
x: Boys
y: Girls
[tex]\left \{ {{x=y+84} \atop {x=7y}} \right.[/tex]
Insert second equation into first one:
[tex]7y=y+84\\[/tex]
[tex]6y=84[/tex]
[tex]y=14\\[/tex]
then substitute y value into second equation:
[tex]x=7*14[/tex]
[tex]x=98[/tex]
