You are trying to find how much younger Kaylee is than Lylah.
You would subtract her age from Lylah's.
45-18= 27
Kaylee was 27 years younger than Lylah.
I hope this helps!
~kaikers
One possible way:
-86+(4*12)=-38
-86 is the number where the diver is. 86 feet below the surface.
4*12 is the total number of feet he has ascended in 12 minutes.
Because he is ascending, so you add 4*12 (or 48) to -86.
The answer is -38, meaning he's 38 feet below the surface.
The diver is now 38 feet below the surface.
Hope this helps.
The given expression is :
2xx+3-5(x-2)
We know that, 

Aleena expands 2xx+3-5(x-2) as 2x²+3-5x-10. She is mistaken because the sign before 10 should be +10 instead of -10. Hence, the correct expanded form is 2x²+3-5x+10. Hence, this is the required solution.