Ronelyse is 4 years older than preston. the sum of their ages is 10. create a system of equations to solve for their ages

In the system, y will represent Ronelyse's age while x will represent Preston's age.
Y=X+4
X+Y=10

If you were solving this system, you'd use substitution and it would look like this:
X+(X+4)=10.
The second step would be to get rid of the four by subtracting it from both sides of the equation which would then make it look like this: 2x=6 (I just combined like terms for x)
The third step is to divide both sides by two to get rid of the two. After this step we could find that x=3.
Our fourth step is to put this into our first equation of the system which would make it y=3+4. Then we'd know that y=7
So, Ronelyse (the y) is 7 and Preston (the x) is 3