Hey there!
Let's write this as a system of equations.
m+b=22
b= 4m-3
Let's plug our value for b into the first equation and solve for m.
m+4m-3=22
We combine like terms.
5m-3=22
We add 3 to both sides.
5m=25
We divide both sides by 5.
m=5
Therefore, Maggie is 5 years old.
I hope this helps!