Lisa and Katie are playing a card game, and a total of 900 points has been scored. Lisa scored 150 more points than Katie. If you let l= the number of points that Lisa scored, and k= the number of points that Katie scored, then the problem can be represented by the system:

l+k=900 and l=k+150
Graph the system. How many points did each of them score?

2 answers

Cannot graph here. I will use substitution.

l = k + 150

l + k = 900

Substitute k+150 for l in the second equation and solve for k. Insert that value into the first equation to solve for l. Check by putting both values into the second equation.
250