Answer:
29
Explanation:
since her age is 3 more than twice her brothers age we'll subtract 3
42 - 3 = 39
since shes twice her brothers age theres actually 3 numbers. her brother's age which is the base number, and her age, which is is that times 2. so in order to get her brothers age we divide by 3
39 ÷ 3 = 13
since shes twice his age + 3 we'll multiply by 2, then add 3
13 × 2 + 3 = 29
I hope this isnt too complicated! I tried to simplify it but I think it came out more confusing than I intended