Larry has 14 toy cars . his grandparents give him some more toy cars . now he has 22 toys cars. which is the equation or in equality that fits this. and determine how many toy cars larry's grandparents gave him. show how determined the correct solution.

14+x=22
I think this will be the answer because it shows how many he already had and it is solvable. 
Subtract 14 from both sides and you get eight.
X=8

Well this is how i would solve that. You know larry has 14 cars. so write that.
Larry=14 cars
Now you don't know how much his grandparents gave him so write that.
grandparents= x amount of cars
Now you know the total amount larry has. so write that.
total of cars=22
Now, this is how i would solve a question like this. i would take the numbers i have and turn it into an addition problem. so it will look like the following.
14+x=22
now it is easy to solve from here. If you subtract 14 on both sides you will see how many cars his grandparents gave.
14+x+22
-14

x=8
and if u wanna check it. all u do is add 8 to 14 and see if it gives you 22. That's it!!