Hey there! I’m happy to help!
Let’s use the variable g to represent the girls. This ratio shows that there are twice as many boys as girls (boys=2g)We also see that there are 18 more boys that girls. Let’s set up an equation
g+18=2g
We subtract 18 from both sides
g=2g-18
We subtract 2g from both sides.
-g=-18
We divide both sides by -1
g=18
Therefore, there are eighteen girls.
I hope that this helps! Have a wonderful day!