i’m not sure if this is correct but this is the way i would solve it.
first, make an equation with the given information
2x-3=30
Then, add three to both sides
2x=33
Finally, divide both sides by 2
x= 16.5
x represents the age of maggie so all you have to do is plug the solution into the equation to check your answer.
2(16.5)-3= 30