First, you know that Jackson (let call her J) scored 42 more points than L (Leslie). What we don't know is how many points L scored so we can use a variable that will be 'x'.
So the equation will be J=42+x.
We also know that the total points is 1,144.
To find out what x is we first subtract 1,144-42. We then get 1,102.
We are now left with 2x and 1,102 so we divide 1,102 by 2 and get 551.
551=x so now we can plug that in.
J = 551 + 42
Jackson scored 593 points and Leslie scored 551 points
(You can use bar modeling to do solve this problem. An example of bar modeling is shown below.